This data is quite a relief because they still believe in Bitcoin even in a crisis, but this data is not guaranteed if next in the future they still hold Bitcoin because as I know, some of them is a businessman or former stock investor who just invest if the asset is profitable. I am really sure by time will reduce significantly after halving y+1, and grow again on y-1 like today. because of many of them as seasonal investors, so we shouldn't rely on it if want to know who the real richest bitcoiners.
Experienced bitcoiners will accumulate cheap bitcoins in bear market and hold it till a next block reward halving because they know after each halving, price will have good growth.
For people who have plans to invest in bitcoins a few years, they will take profit after halving and its consequence price growth. However, you don't have to think of what they do. Your biggest task is whether you own bitcoins and take profit with its block reward halving. Focus on yourself is better than looking at others' activities and what bitcoin whales do.
We are going to a fourth halving in Bitcoin history that would be one of great chance for you before it becomes too late when block reward becomes too small and halving effects become smaller.