DirectX 11 and 12 don't exist on Linux (TF2 also only uses DirectX 9 on Windows). Anyway, not only TF2 is effected but other not well maintained Source games too. The culprit is the newest version of LLVM (and another package I can't remember the name of, but it's a popular one that is always the problem) and that was two months ago (joys of a rolling distro). This problem can only be fixed by that one guy at Valve who still works at TF2 to adjust to the new LLVM.
Edit: it can also be fixed by the package maintainers by reversing that oopsi