Ĉu 'foruziĝonta" signifas same kiel "foruzota"?

There seem to be a lot of people, who are intrigued by the theoretical possibility in Esperanto, that you can take any root and add to it any pre- and/postfix, even multiple ones. Unfortunately given the sheer amount of possible combinations I would say, that most of these combinations do not make sense. Then there is a large grey zone of such combinations, that make sense in a very specific context. The smallest group is those combinations, that are in wide use. I'm inclined to think, that foruziĝi – and its partciples – fall into the senseless category.

• the prefix for- means away
• the root verb uzi means to use
• the combination foruzi means tute konsumi per uzado, e.g. dum la lasta vintro oni foruzis la tutan provizon da ligno : during the last winter they used up all their stock of wood

In PIV there is one verb with -uziĝi, eluziĝi which means difektiĝi pro longa uzado, e.g. tiu ĉi ŝtofo tre malrapide eluziĝos : this cloth will become worn out slowly.

As Eduardo points out, -iĝi means, that the act takes place by itself. PMEG has a whole chapter about the postfix -iĝi. Since foruzi is a transitive verb, "you use up something", the act of using up can't happen by itself, i.e. no foruziĝi.

What seems to throw many English-speakers off when it comes to -iĝi verbs and participles, are two things:

• because of the extremely strict word order in English English uses more passive voice than is needed in Esperanto (and when needed prefer the oni-passive whenever possible because of its simplicity)
• many English-speakers try to map the -ing ending of English into a partciple in Esperanto while the -ing form can stand for different things, not all expressed by participles in Esperanto, see https://esperanto.stackexchange.com/a/3674

Coming back to your example in your comment there is a verb formanĝi : tute konsumi per manĝado, "to eat up".

• La sandviĉojn oni formanĝis : The sandwiches were eaten up.

Or if you need have a future aspect

• La sandviĉojn oni lasis por formanĝi : The sandwiches were left for to be eaten up.

Se temas pri la foruzo de X:

foruziĝonta: la foruzo de X okazos per si mem.

foruzota: io foruzos X-n, kaj kutime tiun informon oni provizas.

Se vi aldonas ekzemplajn frazojn aŭ kuntekston oni povas pli detale respondi.