Now here's something out of no where: Legoland have shared a glimpse into the future, stating their intent to apply for plans for an adventure golf course, with a "new roller coaster investment" on the horizon too: https://www.windsorobserver.co.uk/news/19849032.legoland-windsor-plans-build-new-adventure-golf-course/
They're citing the potential threat of London Resort a reason for these investments:
An adventure golf course will certainly add to the park and resort in a worthwhile way. I honestly think that more and more resort parks should have adventure gold courses - compared to most theme park attractions, even a good quality one is only a comparatively small investment. They are low cost in maintenance, cheap to operate in terms of staffing and you can justifiably upcharge for it.
Plus, I think a Lego-themed mini golf just sounds like a great idea.
The "new coaster investment" is interesting. I've heard rumblings of a B&M going to Windsor. Personally, I think that's just rumours coming from people seeing the Legolands in China and putting 2 and 2 together to get 5. And I would have laughed the idea out the window a year ago. But with Chessington getting a B&M, and obviously multiple B&Ms in the Chinese Legoland parks looking likely, it's not the craziest suggestion right now.
Legoland Windsor has many planning obstacles, and they're low on usable space. Even with the focus on the younger market, they do need another family coaster imo. Their recent dark ride additions have been very 'for all the family' orientated, so having a new coaster catering for that market isn't out of the question. But yeah, will be very interesting to see what they do.
I do wonder if there have been an internal shift in philosophy about the likelihood of London Resort, given it's been quoted as a need for investment multiple times. Again, my opinion would be that they're still not worried about it, and still pretty sceptical that it will ever open, but there's certainly no harm in them playing off it to push through new investments.
Out of all the UK Merlin parks, Legoland has seen some of the most consistent and well thought-out additions over the last 7-10 years really, so this isn't anything new. But it's good it continue under the changes at the top of Merlin (even if it's not a surprise!).