Yes I agree that this is problematic and repeat:
I have never seen a software that could guarantee the project files being 100% backwards-(and forward!) compatible. If they could I would love to have that guarantee as part of a SLA on paper.
Everything else is harmful in a "Studio" environment.
To be honest I would not care what the free version does. I can understand that this kind of forced updates are heaven for support (like with cloud based software) as you only need to support the latest version.
But in Production environments where every breakdown costs you more than software licenses or support contracts do this is useless.
I have not seen an environment yet that would not run multiple suites of software versions simultaneously to drive parallel shows.
I hope that with the Linux version in the making professional studio environments will be considered in BMDs future strategies. I'd be glad to discuss.
EDIT: Just to be clear, I only mind Fusion overwriting older versions. I do not mind Studio overwriting non Studio so much, other than it makes writing a review for both painful