Back when Bill Gates was still in his dad's ballsack, I was using UNIX on mainframes.
When he finally got out, and was flapping around on the lounge room rug, we were using PDP-7 and PDP-9's (which were 18 bit..)
Arguably, the OS on these were lesser-UNIX style and more FORTRAN.
But then came the PDP-10 and PDP-11, a bunch of DEC hardware which cemented the way forward to UNIX(like) OS.
None of this hardware cared about Bill's "DOS".
In fact, the last "upgrade" (sad to say) I did, was a BSD based Solaris SunOS around 2005 (at which point MS had acquired it as Santa Cruz Operations (SCO). Where the company I worked for had let go the 'unix' software for "modern" windows and no longer supported the customers in the old version.
So to answer your question about locking down bootloaders, it made no difference. MS DOS was never gonna run on the main steam hardware that was prevalent at the time. Not because it was locked in with us, but because we were locked in with it.
Seems they might be listening. If their first two hits are 'community development' and 'creative director', then we can only assume they have probably come to the same conclusion you have stated.