I agree with chefo that there will be no effect on the calls on TRX2 but do not agree with limitation of TS 0 & 1. Chefo u forgot that in case of BCCH shift the whole ARFCN gets shited to 2nd TRX. so in that case there won’t be any non bcch ARFCN & hence calls that were earlier on non bcch TRX will be dropped.
Lastly the fascility that BCCH always remains active in a cell by shifting to some other TRX in case of a HW failure is a vendor provided fascility.
Hope this clears all ur doubts.