The FSF isn’t a mathematical enterprise dropping out nuggets of code whose value is unquestionable, like pure mathematical truths - it’s a lobbying organization. And for a lobbying organization both 1) credibility and 2) having supportable goals
matter.
If you believe there is value in campaigning for increased freedom for users of software, then you might benefit from the FSF having concrete campaign goals and the ability to be taken seriously.
Inviting RMS back to the board does not help them in that regard.
Your ability to benefit from the software produced by RMS has no dependency on his being elevated to a seat on the board of an organization whose opinion might be sought, say, if congress were debating laws mandating access to source code of voting machines.