...the other TOS books coming out this year (which I'm guessing will also be focusing on the end of the 5YM)...
I don't think that's likely. The TOS books these days tend to be pretty much standalone. There was a bit of overlap last year between The Rings of Time
and Forgotten History
, but that was entirely because Greg and I were both doing time-travel stories and thus chose to compare notes and acknowledge each other's books. And even that was just a passing mention both ways.
(And of course Forgotten History
actually depicted the very
end of the 5-year mission and the events leading up to and growing out of it.)