When it comes to incremental releases, ExtendSim is upwardly compatible. For example, a model or block created in ExtendSim 2024.R1 can easily be read in by ExtendSim 2024.R2.
However, there could be application or block changes in newer releases that would impact file readability in older incremental releases. For example, if you save a model in ExtendSim 2024.R2, you may not be able to successfully open it in ExtendSim 2024.R1 (and definitely not in ExtendSim 10 or earlier).