Heard the NSO RVP had a write-up about this issue in an email last night. Basically, it boils down to this: the Agency doesn't want to re-open the Slate Book during the current Biden Administration and NATCA doesn't want to have to negotiate with a Trump Administration.
The question presented to the NEB was, under various scenarios, what to authorize the NATCA President to do? Extending the CBA to 2029 was not palatable; but, the question then was, what if an extension to 2029 came with an early opener for 2026? Extending to 2029 with an opener for 2026 was a little more palatable... but not by much. The question then was, what if the Agency said "we offer you an extension to 2029 with an opener in 2026 and you must accept by this date or there is no extension," period. Of course, the drop dead date would be prior to the November presidential election. And, that is what the NEB voted to decide.
Quite simply, no one wants to extend the Slate Book to 2029 but the FAA Administrator of "the most friendly labor union President in history" (trademark) won't agree to re-open the Slate Book during the Biden Administration and is very likely to say "take it or leave it" to an extension before elections. This is the disastrous Paul-Trish NATCA (lack of) leadership coming back to bite us in the ass and every single member should be prepared for BOHICA.