Is "Not that we would have expected anything else, of course" sound?

“Not that we would have expected anything else, of course”

Sounds like cynicism: our expectation, if we were optimistic, would have been that the company did x, but because companies are [e.g. inherently evil], hence the "of course", that is not the case. Rather, said company did y action.

There is a tinge of inevitable, almost natural, disappointment in the phrase.

The modal form is a likely choice. In my opinion, saying "a company did something expected" is going too far or not providing a clear basis for the question as it is first of all too vague: what was expected, a statement, or the tenor of a given statement, or, even, a statement and the particular tenor it was found to have?

It seems from the context that the statement is not what was expected; how could that have been the case? It is true that this type of announcement is sometimes notified publicly as a formal communication to be made in the near future, or also that it is customary to issue such statements more or less automatically in some circumstances; then it can be said of the statement that it is expected; nevertheless, this would not be relevant: one does not comment this way on the realization of such expectations except in rare contexts (when the statement is never or rarely made, for instance, by a certain agent known for failing more or less regularly to abide by their word). No, I think it can be surmised that a statement was not expected, and that, would it have been the case, then the recipients would not have expected a different tenor of it. On the contrary, if the statement was expected, then the modal would have to remain unexplained. In a sense, this use of the modal "would" allows one to mention a hypothetical evaluation of the tenor of such a statement in the light of knowing that it would be delivered sometime in the near future, or, simply, the position of the firm if one had wondered about it relative to the business at hand; moreover, only when getting to this sentence containing the modal can we infer what the expectation could be.

Not that we would have expected anything else, of course.

Why not just say the following?

Not that we expected anything else, of course.

I am surprised that you did not ask “Why not just say the following? “We expected nothing else”?” Why are all the other words there?

The negative is used for emphasis – this is a figure of speech called “litotes”: noun noun: litotes

1. ironic understatement in which an affirmative is expressed by the negative of its contrary (e.g. I shan't be sorry for I shall be glad ). Definitions from Oxford Languages

The writer has a motive: He is expressing an opinion and wants you to agree. And he is using rhetoric to get your agreement.

Not that we expect anything else, of course – this implies that you and the writer are in complete agreement. But, by making a direct statement, the writer has been presumptive: he has assumed your agreement. Psychologically, if you wish to have someone agree with you, this is not a good idea.

Not that we would expect anything else, of course “Would” implies a good probability that you and the writer agree, but allows for the fact that some people might not. “Would” is often used to encourage your agreement – it suggests that the writer thinks that you are a reasonable person (like he is) and would therefore agree.

Not that we would have expected anything else, of course.

Why not just say the following?

Not that we expected anything else, of course.

I am surprised that you did not ask “Why not just say the following? “We expected nothing else”?” Why are all the other words there?

The negative is used for emphasis – this is a figure of speech called “litotes”:

1. ironic understatement in which an affirmative is expressed by the negative of its contrary (e.g. I shan't be sorry for I shall be glad ). Definitions from Oxford Languages

The writer has a motive: He is expressing an opinion and wants you to agree. And he is using rhetoric to get your agreement.

Not that we expect anything else, of course – this implies that you and the writer are in complete agreement. But, by making a direct statement, the writer has been presumptive: he has assumed your agreement. Psychologically, if you wish to have someone agree with you, this is not a good idea.

Not that we would expect anything else, of course “Would” implies a good probability that you and the writer agree, but allows for the fact that some people might not. “Would” is often used to encourage your agreement – it suggests that the writer thinks that you are a reasonable person (like he is) and would therefore agree.

There is also the possibility of a "hidden if-clause" = “Not that if we had been asked to consider the matter, we would have expected anything else, of course”

But this boils down to much the same reason for choosing "would".