Oh I also received a notification about Patreon Merch and I think it's cool that Patreon can provide a service like this. However I do worry about what the quality of the merch as well. Currently they offer stickers, mugs, and T-shirts. The merch is only applicable to $10 up tiers where patrons can get a merch if they stay in the tier for 3 months and the merch will automatically be prepared and shipped by Patreon themselves. It also says that aside from your initial plan, example your patreon plan is 5% cut they will add another 3% cut to your overall creator's balance.
I haven't tried it cause I'm worried about the additional 3% cause I don't really know if it's really just 3%. I only earn a little more than just $200 and I don't think that would cover even 1 merch for one patron. So I'm giving this a rest and if one day I'm earning more than 500 or maybe a 1000 then I'll consider merch. Additionally, I also don't have a design that patrons would want to even get so for now, I'm just happy that Patreon has this kind of service. At least I know when I have plans in the future.