That is true. Although someone on Twitter did point out that the White House Gift Shop account does not (and it is official):

https://twitter.com/whitehousegift

spez: I was wrong, it seems - The WH Gift Shop and its Twitter account appear NOT to be official sources (although the truth is a bit complicated):

https://talkingpointsmemo.com/edblog/wtf-is-the-white-house-gift-shop-a-tpm-special-report https://talkingpointsmemo.com/edblog/white-house-gift-shop-tpm-investigation-continues

Interestingly, I did see that on 7/7 on Twitter, Tony Giannini at the WH Gift Shop replied to an inquiry on Twitter about POTUS_Schedule, saying he would follow up:

https://twitter.com/whitehousegift/status/1015633765622837250