Their scope for "growth" which we all know is what the stock markets holy grail, is somewhat limited within the UK market, up against the likes of TUI. Jet2 have already based aircraft in Spain, so it wouldn't, for example have been that great a step to begin operating to places like Cologne, Stuttgart, Rotterdam, Billund - I've picked those places out, not because they are necessarily viable, but because they are in countries where the flay on words that is "Jet2" only really works in countries where there is a good working knowledge of the English language and it's nuances. Then of course the easiest market to enter would be Ireland, and having registered aircraft on the Irish (EU) register they could very much do an "Aer Lingus UK".
For now, rebuilding the business as and when covid restrictions allow has got to be their, and every other airlines number one priority, not potentially risky ventures into the unknown on vanity trips.