I think you're confusing standards with partners.

I doubt there's a permanent standard that Marriott must have Thann. I bet the standard actually says it must have something that has this quality, etc, etc, and Thann is the current partner that meets that.

Pepsi vs a competitor is again not a standard, it's just a partner.

Standards are like what is the minimum that a Marirott can have in a lounge if it has a lounge, not what brands it has.

Standards are like what is the mimimum wifi speed and reliablity that a Courtyard can have, not what brand of routers it uses.

Standards are like what are the minimum items that a Fairfield has to serve at breakfast, not what brands they are.

So if you want to know what brands are present at properties, that's different than what the standards are. So which is that you're asking about?

I'll tell you one standard I do know about, because it was announced in press releases. Fairfields now have to have"'freshly scrambled" eggs. That's very cleverly phrased, because it doesn't mean the eggs are fresh (no, they're usually powdered, and you'd wish they'd at least be EggBeaters), it's just that the powdered eggs were scrambled that morning and so they're "freshly scrambled" . I hate powdered eggs, so the other Fairfield brand standard, which I haven't seen in print but always so far in practice, is hard boiled eggs too ^.)

Btw, I can tell you that the brand standard does not require fresh eggs to be used for the scrambled eggs at a Marriott FS lounge. (I wish it were.)