In previous updates you lost the "good coms" they were converted to the lower coms. Extra was turned into credits. Just because it is currently like this on the test center, doesn't mean live will be the same.
Granted those were champion and BM coms etc, but I don't see them letting us be geared out completely on day one.
I would be ecstatic if it were otherwise but we will see.
Um, that sounds like what happens in WoW, but having played since early release and having 5 50's, I don't recall this ever happening in SWTOR. When EWH came out I was able to purchase pieces the second I logged in, didn't lose any comms. Dunno where you got this, unless you're thinking of WoW but I'm 99.999999999999% positive BW has never done this. (except the ORIGINAL conversion from battlemaster, champion, centurion marks to the current comm system)