Also, these "international" markets are becoming increasingly regulated.
It's REGULATION that they are running away from, not the UK players, a market that they previously say was delivering "incredible growth". It is likely that others will follow the lead of the UK, and also France, Spain and Italy that took a similar approach before the UK, and there will be more "running away" from one market or another. The supply of new "lightly regulated" markets will also diminish, so in the end, they will have to come back and compete in the "new order" that will emerge, but they will be at a considerable disadvantage as the incumbents who stayed and evolved with the regulations will have the advantage, and are likely to see off all but the best of the newcomers.
In the end, they will be left with those countries where it wasn't lack of regulation that scared them away, but the endemic fraud and "bonus abuse" that existed in those countries that led casinos to previously have them down as "banned countries".
I remember when some casinos listed the UK as a "banned country", but when they started to lose their grip on the huge US market, they could no longer ignore the UK market as it's one of the biggest gambling markets in the EU. Suddenly, UK players were no longer treated like pariahs, they were actively being attracted to play in the same casinos that once listed the UK as a "banned country".
Maybe they are relying on the biggest gambling fan base of all, the Asian market, where laws prohibiting online gambling are freely ignored by players, and barely enforced by the authorities. Very much how the US market used to be before 2006, UIGEA, and the beginning of a determined drive by the authorities to drive the offshore operators out of the US marketplace by fair means or foul.