If it's FOSS (funded), no amount of money autodesk throw at it can bury it's source code, buying it would guarantee to some degree a future in the software and thus your investment. Even if autodesk bought the originating company.
But this would take a widespread cultural change in the values of architects combined with the first company willing to gamble on that business model. If a large group of architects are willing to sign a letter like this, perhaps now is the opportune moment to try and spread that value to avoid this problem in the future.