Of course you'd be able to receive email at that address, but you cannot have that email address be hosted for free at Google. You'd need to self-host, or pay somebody else to host email for that domain.
Ah yes, I feel like I totally forgot this. Thank you for pointing it out — you could totally just change the MX records and still use Workspace. I stand corrected! Thank you, Jason!
So back to the days where you could make a Google account with any email address before gapps exited. It was such a mess once domains where moved to gapps to know if it was a legacy account or gapps account. In fact I will still get prompted for some addresses.
> So back to the days where you could make a Google account with any email address
You can still do that, and it's not some obscure feature but asked about on the first page of the account creation flow with the "use my current email address instead" button. It'll be a fully functional Google account, except for supporting mail, and can be changed to a gmail account later (that feature is obscure though).
My guess would be that these legacy accounts will end up as something different than a consumer Google account created with a non-gmail address, but guess we'll see once it launches.
Info? Because Google Apps for your domain also known as G Suite (legacy) is the method we've used for this and is going away as a free option. The other approach is to integrate a free gmail account with a mail hosting provider. You can use mailgun or similar to do it cheap but it still means you host your domain email server somewhere.
I'm experimenting with CloudFlare's email forwarding (currently in beta) and it works very nice. Also, it's free and doesn't require changing registrars.