Concerns have been raised on their future recently.
https://www.thetimes.co.uk/article/legoland-owner-sounds-the-alarm-over-its-future-ms6b6kh8z
But Merlin did also change ownership hands recently to the Lego (Kristiansen) family. I think that puts them in much more stable hands than a few other park chains.
I haven't followed them at all. Were hoping to go to the florida one in sept so we shall see