I always tell my kids what's happening. I like to prepare myself for the onslaught (if there's going to be one, lol).
FWIW I think it's a good thing you tell him about it. It prepares him for it & it's not a surprise when you pull into the driveway. If you spring it on him I'd think that he would end up being anxious going places JIC you were taking him 'THERE' again.
I found my girls didn't adjust to daycare that well only going one day per week. Claudia went 2 days per week towards the end as I was preparing her for school in Qingdao which is 5 full days & I found she adjusted better going twice per week. She tended to remember more of it & made more friends - I know that is possibly not an option, but it's just what I found.
Also, I always talk it up. 'Mummy wishes there were daycares for grown ups, I'd love to be painting & playing in the sandpit & eating fruit at a table with all my friends', that kinda thing.
Good luck! But it seems he is adjusting after your latest post!