Not to defend anything because I simply don't know the true circumstances at the park behind the scenes and so couldn't comment either way, but, I did want to address a couple of points:
First, saying that their animals are under veterinary monitoring shouldn't necessarily be considered an automatic admission of guilt. That's just good husbandry, even under the best of circumstances with perfectly healthy animals. I don't think it automatically implies that there's something more going on, although of course there absolutely could be -- I just don't think that particular statement gives that away.
It's also important to consider, regarding the proposed purchase of Russian killer whales, that China drove prices for wild-caught animals up exponentially and outbid essentially every other facility attempting to purchase them. Not just killer whales, either -- for example, bidding for walruses rose around 100x the previous starting prices, and could go into multi-millions of dollars per head. Imagine then how much more a killer whale would have cost. I don't know the park's financials, I'm not sure how feasible that would or would not have been.
I want to stress again that I'm definitely not defending anything -- I couldn't even if I wanted to, I feel like I simply don't have the necessary information to be able to take a definitive stance

Only offering a couple of counterpoints. I wish all the best for their animal collection, whatever form that may take as decided by the persons involved. Marineland is up for a lot of changes in their future either way; it's going to be very interesting to see how they adapt.
Edit: One thing I will fully, whole-heartedly agree with: their PR and general social media management is outright horrific, lol.