Exit criteria in the wake of 3 engines

In exit criteria for many of the specs we see text like: "each
implementation must be developed by a different party and cannot share,
reuse, or derive from code used by another qualifying implementation"

With Opera adopting Chromium, this criterium appears to have gotten
significantly more challenging to satisfy.

There were 6 two-implementation possibilities with Presto and without, that
number is reduced to 3.

Is revisiting the exit criteria worthwhile now that it seems far more
difficult to move a spec to Rec?