Absolutely. Not only that, but we'd never know if these institutions are accumulating from the OTC market. There is really no way of knowing exactly what a corporation is doing internally in terms of adopting crypto.
The fact that there is no way to figure out who moves Bitcoin from address to address shows that Bitcoin is doing its job well. I'm sure that institutions like that bit of 'privacy', and we all do.
I am however not sure if institutions are legally obliged to disclose their current holdings, but it would make sense if so. It's mostly client money they invest, and they do deserve to know what is going on in the background.
I would not doubt if at least some of these traditional financial institutions were able to spot the bottom and accumulate coins while everyone else was still concerned about the bear market. After all, that's when the smart money starts to flow into the market.
Institutions pay attention to the technicals, and what's better than buying into an asset that has gone down with more than 75%? Much better than many of the stocks that hover around all time high levels.