2 recent Hyatt stays:

1 - Was given a bill to sign, added a $4 tip. At checkout was told I had my room, tax and a $4 restaurant charge, so clearly that tip was not included.

2 - Other property gave me a coupon/voucher. It did not state if tip was included, so I ended up leaving cash. (Only had $2 in my pocket, but would have left more if it was something I could have signed to my room.)