[pbhjpbhj]

Not the OP but will a company wait 7 years so they can use some (F)OSS without providing their source modifications?

Seems unlikely, but if they do and those modifications are super-helpful then at most you'd have to wait 7 years to use reverse-engineered versions (disregarding patents), more likely you could reverse-engineer the mods and write technical equivalents using fresh code (ie clean-room re-writes).

Seems to me like it would still work in practice.