[Chris Jerdonek]
I don’t think we should assume that a stalemate would be okay in all cases. There may be cases in which a decision has to be made (e.g. if nothing changes, bad things will happen). I think one of the most important roles a BDFL serves is to provide a mechanism of last resort to resolve such stalemates should they ever arise. If the replacement we come up with can itself stalemate, I think there will be a problem.

Can you flesh that out with a plausible example?  If "bad things can happen" relates to finances or legal issues, the problem is almost certainly the PSF's headache to resolve.  If they don't relate to finances or legal issues, I'm unclear on what "bad" could mean.  Guido's BDFL pronouncements were mostly about language and library design issues.

The only total stalemate I can recall happened when complex numbers were added to Python.  Should the suffix used to denote imaginary literals be "i" or "j"?  After long argumentation, nothing anywhere near consensus was reached, in large part because there really isn't a _compelling_ argument for or against either one.  Just observations justifying personal tastes, sometimes disguised as "arguments" (whether "i looks too much like the digit 1" or "j is rarely used by mathematicians").

Guido picked "j".  The world wouldn't really be significantly different if he had picked "i".  If the Elders childishly refused to compromise, then

    print(random.choice("ij'))

could settle it ;-)

Here's a hypothetical:  suppose Larry removes the GIL but it slows down single-threaded code by a factor of 1.2.  Should the default CPython provided by the PSF enable that or not?  That could plausibly become a contentious issue with no community consensus.  If the Elders tied, the "no change" (maintain the status quo) outcome would still be _a_ resolution.

If you want to make a rule that the Elders cannot tie, the only way to do that is to say they'll all be impeached and replaced if they ever tie (as already noted by Łukasz, having an odd number of Elders doesn't prevent one from abstaining).  And we'll keep replacing them until they stop tying.  But we'll probably run out of volunteers after the first round of impeachments.

Sneakier:  add a rule that if the Elders tie, then the choice has to be made by the President of the PSF.  Which, by sheer coincidence, is Guido :-)