If you read recent posts in the Gold Card Refresh thread, you'll see lots of discussion of, for example, restaurants that use Square posting as 1x instead of 4x, despite showing a category of RESTAURANT. So, yes, you do want to pay closer attention, so you can take whatever action you prefer (some people in that thread, once they identify which restaurants are not posting as 4x for them, decide to use a different card at those restaurants, while other people prefer to complain to Amex) as soon as you know there's a problem.

As to "ever", I don't know how many people used a card with bonus MRs at restaurants before (that wasn't a bonus which posted bonus MR points instantly). It's the touted 4x at restaurants that's making everyone suddenly turn to the refreshed Amex PRG->Gold card for their restaurant purchases. And it's on restaurants that the main failures (unrelated to Category issues).

Category issues can be identified before the points post. If you buy something at a stores excepting it to code as Grocery and thus get bonus points on that, and it codes as Gas Station instead, you can tell you won't get the Grocery bonus points just from the listed Category on the transaction shown on the Amex website. So that's why seeing the bonus points "early" is most important with bonus points that can be messed up for some reason even when Category is correct, which I've not heard of happening outside of the Restaurant world before.