There's no definite truth about his patreons since only him has the real stats. But we can get an idea of it by checking the patreon stats. In the last year most porn games have seen a surge in popularity and number of patreons. FOr the sake of comparison I'll post some stats from other Honey Select devsAny hard numbers to back this up? Apart from the few ones here declaring so, there's just no way for you to know how many patreons he has actually lost and got replaced, again just assumptions.
Waifu Academy by Irphaeus
Ecchi Sensei by BlueCat
Harem Hotel by Runey
Mythic Manor by Jikei
The Headmaster by Altos and Herdone
All the other game devs got at least 50% in the number of patreons (The Headmaster being an outlier), while Irphaeus only got a 25% boost. It's likely that the number of patreons didn't increase that much because it got countered by the number of people that stopped supporting him.
Another interesting data I got is that most of them that revealed their earnings showed at least 9k-10k around the 1200 patreon mark, so it's safe to assume he's pocketing 10k a month