They will keep the CTC brand, in the UK at least. The deal wasn't really about the UK though, and want really about closing operations, but about avoiding having to open new ones.
Wiggle's main strategy is to roll out internationally to less mature markets where the competition is a bit less intense and where they can potentially get better margins as a result. CRC was already in some countries where wiggle wants to be and it is quicker to buy rather than build up the operations from scratch.
The northern Irish operations were essentially a bit of collateral damage / extra savings, from serving both websites from one back end.
The closure of the NI operations would have been part of the deal valuation though, and wiggle would have paid the previous owners a sum to reflect the value of those savings.