I hope people aren't taking this CM advice at face value. I've already seen at least one person report that they were told they shouldn't even be messing around in MDE, let alone trying to FP+ or customize MBs if they hadn't gotten an emailed invitation yet. Very unpleasant about it. The problem is your MBs are supposed to be sent out 30 days before arrival, so you can't generally customize them any closer than that. So, unless there are no MBs associated with the reservation and they just happen to get added later, in time to customize and ship to home or resort, you're going to end up with plain gray bands if you sit back and wait.
It's possible that you're not eligible for MBs for some reason, of course. But the roll-out is basically to all the resorts at this point, depending on check-in date. So you've either got eligibility and should be able to customize now for November or you're not eligible for some reason. I really wouldn't just sit around and wait. The FP+ should be the same situation, except you can do them right up until their times, so less pressure now.
BoG FP+ is a separate issue, literally in the computer systems and figuratively. We've had reports of people who couldn't get into the system (mostly resolved) and people who got in but couldn't book or who tried to book and didn't find availability. We've also had reports of people who got in but then found they couldn't log back in to their accounts later on.
Myself, I didn't get any email invite (for anything, and we arrive 10/31), but I was able to access the BoG FP+ system and booked a time within our first 7 days, which seems to be the limit. I screenshotted my reservation info, just in case. But we've already had people report that they didn't get an email inviting them to do BoG FP+ and they got a FP+ anyway and were either on a list when they arrived at BoG or were taken at their word (or proof) and let in. We've also had reports or people asking at their resorts at check-in and having the CM book them BoG FP+ without any questions.
As always, the CMs don't necessarily have the latest or most accurate information, and it makes me very sad to see people treated poorly by a CM or advised to give up and wait for something that may never come when others were able to get these experiences.
There is no way Disney sent out limited invites to BoG FP+ without a special individual code or other system to keep non-invitees out if they expected to keep the pool limited to only those specific people. And there is no way they encouraged people to sign up for MDE and then put the MagicBand customization and FP+ links on there if they didn't intend for people to be customizing and signing up. If they planned to limit access so tightly, they wouldn't have made it so easy for so many others to get access. And they're so close to full roll-out to resort guests at this point, that waiting around for them to specially invite you when emails could get lost or computer glitches could occur is just asking to miss out on something.
We're informed WDW visitors here. We don't wait around for an email telling us the dessert party is open (now open until March, apparently -- which is a big change) or our ADR window is open -- we actively pursue these experiences that many WDW visitors never even know exist. We know things book up or get released early or have limited access if you know how to get it (we previewed New Fantasyland last year with
D23 and then went back several other days and were allowed in just because we asked!). And we know things are closed for refurbishment so we're not disappointed or can change our plans.
So, to see people being advised to just trust contradictory advice from one CM is worrisome to me. I don't want anyone to miss out on something they could otherwise do. There are plenty of threads on these subjects ongoing right now, and they all report varying degrees of success doing things CMs have told us won't work. And you'll never know if you don't try. Always hope for pixie dust!