UK base - maybe, but those within are seriously hoping this will not be the case. There are literally hundreds in both seats awaiting transfers and any parachuting of DEPs into UK bases with long waiting lists is going to cause tensions. My option only, so who knows?
Who would it cause tension with? In my experience that would surprise absolutely nobody in Ryanair. Last time I checked the basing system was at their mercy and there was no transparent list - seniority or otherwise. In my opinion if a DEP gave Ryanair an ultimatum of UK base or nothing they would give them the UK if supply and demand warrants it. Given the lack of union membership the company can do what they want.