[vog]

> this requires automated procedures to convery any event version N to another version N + 1, but having these kind of procedures in place is good practice anyway

Note that this "good practice" already has a name, it is usually called "migrations".

Migrations may be as simple as SQL Update / ALTER TABLE statements. But they may also be transformation of JSON/XML/... structures, or any other complex calculation.

It may not be the best term, as "migrations" usually imply that the result is written back to the data store. But apart from that, I don't see any problem using this term here.