I haven't done anything i the current round of checklist-only shops, but there was a different client with checklist-only hotels and a similar warning earlier in the year. I didn't have any issues with it.
I think the warning is there because while it would be really hard to fake an interaction for a standard Coyle assignment with heavy narrative required, it would be much easier to simply check a few items as present or not present, instead of not looking for them, when narrative is not required....and that's where we get into why I don't find the current shops very appealing. They are not service-oriented shops.
The shops currently posted are more like audits, and I'm not a fan of audits unless they pay really well, and include all expenses. A service assignment has you posing like a guest and enjoying all the hotel benefits, and can written up after you leave the hotel. An audit has you working most of the time you are at the hotel, and working on things that are not that interesting. It's not a vacation, and doesn't fit well in the 'lifestyle' type shops that I enjoy.
As far as having a shop rejected for details, also consider that for a service audit, a standard might be that you are greeted with 2 minutes of being seated for dinner, or that you are offered coffee with dessert. Very simple items to gauge, and difficult to refute. An audit might say something like 'a fire extinguisher must be visible in the dining area'. Now....that's a harder thing to gauge. It's not only potentially more time consuming, but it's not an enjoyable task. Instead of enjoying a meal and taking a few notes, now you have to run around the dining area looking for a visible extinguisher....and when you don't find one, but then the client sends a picture of in an alcove near the women's restroom that you didn't go to, that's when the lack of reimbursement issue comes into play.
Just something to consider when salivating over no-narrative shops....I mean, audits