How does the GPL help with this? Google could build their own libc replacement, and if they push it hard enough to gain widespread community support, it could become the (or at least, a) new standard. At that point Google is free to do whatever they want with it as long as they make it useful enough that the community won't abandon it. The GPL just means that it could be forked later, but if Google is still putting significant resources into developing the main branch then no-one will switch to the forks.
This. I definitely sounds like they want a libc that they are free to fork and add proprietary incompatibilities to, which they can do with the GNU libc (under LGPL) as long as they don't want to distribute it, so we can assume they want to distribute it and that this is a further closing of their consumer tech like android. I would've though musl would be a better starting point for them.
