The FSF is not a new organization. That it cannot function without RMS means it's failing to stand on its own. That may be acceptable for a new organization but in case of the FSF that's just a massive failure to build a sustainable organization.
If you care about the work the FSF is doing (I don't), this announcement should be extremely worrying.
Imagine a company welcoming back a founder who was forced out for some sort of highly questionable behavior and public statements--and the company to come out with a statement a year later that they just couldn't go on without their founder's wisdom. We would rightly say the board and senior management of that company wasn't doing their job.
I agree it's slightly worrying, there's currently no replacement for RMS. The libre software movement risks falling apart if he is no longer there. FSF and RMS should make quick work of finding someone valuable.
But with bacon my life is better, fuller and more pleasant in all aspects.