Listening to Normal Pilot, it seems your experience is very much base dependent.
STN is unsurprisingly losing people left right and centre to BA, Thomson and occasionally EZY and are very short of crew with many requests for people to work days off. Smaller UK bases are finding things fairly easy as there is such a queue of people to move to them that any leaver is easily replaced by somebody on the continent looking to move back home so the effect would be less likely to be felt locally.
The northern UK bases I believe were less hit by BA as commuting seems to be less appealing. There are a lot of DEFOs from turboprop and commuter backgrounds who have been hired in expectation of being able to upgrade 12-18 months down the line to plug the command gap left by experienced FOs leaving.
I think they will probably just about muddle through as they have done in the past but another busy year ahead for those remaining.