How likely is it for an end portal to already be "complete"?

We already know that in Minecraft 1.16, an end portal can generate with 12 eyes of ender already placed, such as in the seed -4530634556500121041. The odds of this are calculable: 0.1^12 = 1 / 1 trillion.

Recently the seed 2483313382402348964 which generates the following end portal was discovered:

For all practical purposes this is a complete portal, since it gives immediate access to the end. Then the actual odds of a "complete" portal are higher than 1 / 1 trillion. Do we have an estimate or actual value for the odds of a complete portal, including this case?

I’ve noticed that the completed part of the portal is in a different chunk than the rest of the portal, which is probably a hint as to why the generation happened like this.