There might be other apps out there with similar issues. I’d recommend checking any critical apps for updates or notices of incompatibility before upgrading the OS.
One reason to hold off that I knew about was if kids (or adults) were playing Animal Crossing Pocket Camp. They posted a notice in their app that the existing version would no launch on iOS/iPadOS 14. They initially said the update would be out later in the month but it was available this morning.
Comcast reached out to me by e-mail saying that “a new setting released as part of the iOS 14 update to your mobile device’s operating system could alter the way the MAC address behaves on your device. If the setting is enabled on your device, the MAC address of that device will change for each WiFi network you connect to.” Thus you could have trouble attaching automatically to your home wifi network. Has anyone experienced this?
Well, this is not a bug, it is a feature: 
It is basically a means to prevent tracking using WiFi. You can always turn off private addresses for certain networks. That would make sense for your home WiFi network for instance, if you should encounter issues.
Leave it to Comcast to make it into a problem!! LOL
+1 for recommending the plunge to iOS 14. I updated both my iPhone and iPad and am loving all the thoughtful features. Everything seems rock solid so far 
I’m seeing my devices on 14 and watch on 7 show up as “new devices” in Eero, presumably due to the MAC address change. I wouldn’t mind an update from Eero to give the option to automatically match certain host/device names.
I saw that, too, with our eero. We have a Circle device, to filter content for our young daughter (beyond what the eero+ account can do). I previously had the Circle set to add all new devices to a profile that blocked certain types of content, and the MAC randomization was constantly dumping my devices into that profile. Once I turned off MAC randomization on my devices, for just my home network, all was well again.
I had turned off private networking for my home network on the two devices I was using to beta test iOS/iPadOS 14 but forgot to make the change on the other devices upgraded to the official release until I received numerous notifications from Eero about new devices.
I’ll have to remember to do the same when I get to the other Eero network I manage plus any other trusted networks or those which have difficulties with MAC address cycling.
I’m now going though apps disabling local network device access for all that don’t require it which is nearly all of them.
I’m both excited and nervous about the widgets. I’ve spent years carefully tuning the first couple pages of apps. More important apps towards the bottom, few folders. I’m afraid of losing that muscle memory. And yes, there’s a lot I can change. I shouldn’t need 2/3 weather apps next to each other, 2 maps apps, or 3 remote apps I never use. And there’s apps I use sparingly, but would never remember the name (iComfort/myQ). And what new widget will appear in 2 months, asking me to readjust what I already adjusted. Hence the paralyzing fear.
So it sounds like it generates a private MAC address every time that it connects to a network? That’s fascinating.
From the K-Base article.
To reduce this privacy risk, iOS 14, iPadOS 14, and watchOS 7 use a different MAC address for each Wi-Fi network. This unique, static MAC address is your device’s private Wi-Fi address for that network only.
Yea I read that but it wasn’t clear if it is the same private MAC address per Wi-Fi network or if changes MAC addresses every time it connects. It sounds like it is the latter which is why everybody has to disable for their home Wi-Fi
I didn’t download it yet, but how is the new search in iOS 14?
I finally took the plunge and upgraded to iOS 14 on my iPhone 10S. I was forced to do it by my purchase of a new Apple Watch, which I love! I have iPadOS on mu iPad Air, and will be putting it on my iPad Mini soon. All good so far!
Your watch arrived already? Nice! Mine should arrive today.
And if anyone needs some amusement this morning: while tracking the watch’s travels with UPS, I noticed that it arrived in Anchorage about ten hours before it left Osaka. 
Looks like Apple have conquered time travel
The time travel reporting is common but does make for a chuckle every time I see it. With Japan/Hong Kong/China being 8-9 hours ahead of UTC and Alaska being 8-9 hours behind UTC, it’s likely to cross a day of the week boundary.
I actually arranged for in-store pickup at an Apple Store. There was no waiting for it to ship; it was available immediately.
Unfortunately that wasn’t an option for me. There’s an Apple Store just over a mile from my apartment, but it’s still closed.
Still, I’m impressed with the speed of shipping. I ordered the watch last Wednesday, it shipped on Thursday, and it arrived before noon yesterday.