BS didn't merge with TU because we lost the war with GS. As far as I remember, we didn't lose cities to GS, except for those inactive and if we consider the rankings (ABP, DBP etc) we were above GS.
As for the BPs, Sab, don't worry, you'll still get those. I'm still your neighbor and I'll continue with the operations just as before. My location on the map is the same, so you can't say I've disappeared.
Regarding the merge, BS and TU members considered it was beneficial to both sides, taking into consideration the old bonds we had and the upcoming upgrade to 2.0. Consequently, you can now see on the map our new name, Evolution, which I assure you will not let you sleep peacefully at night.
As for the challenge, I might say that the war with GS wasn't a challenge up until this point either. For me personally, it was as if I was playing with a little child and I cannot name this a challenge.