The amount is not that much, but still, if it will be used for holding purposes then the demand will increase oversupply. Simple as that. How many of you found it a good news?
Not that much for him, but Jesus....I'd never have to work another day in my miserable little life if I had that much bitcoin (lol).
You wouldn't have to work even if you had 100 BTC, to be honest.

I don't know how old you are, but in my case a mere 50 BTC would set me up for the rest of my life.
I'm not so sure about your assertion that Saylor's purchase is going to have an effect on the supply/demand curve. Bitcoin has gone up a little bit since this news, but the market cap is such that there would have to be a massive, massive purchase made in order to have an effect on the price.
If he was buying on exchanges it would have an effect. Just look at the volumes that move the price. On September 19 someone bought 250 BTC on bitstamp and that moved the price from 27k to 27450.
You can expect that a spot purchase of 5k BTC would get us at least 1k up in price (globally), but this whole week we haven't seen anything like that.
I believe institutions are either buying OTC, or setting buy orders and waiting for scared people to dump into them. Setting floor purchases doesn't affect the price, but takes a lot more time to complete, whicjh they have. They've been doing this for the last year.