In the same boat, sold laptop without resetting properly

In a similar boat. Sold MacBook Pro (mid-)

2015) but forgot to reset it before sale. Thought I did but later realized I didn't. Silly. It's running Monterey with the latest system update the old Intel processor could take.

So, using Find My, I set the laptop to erase and put an activation code on it. I did not remove the laptop yet from my Apple ID.

Questions:

1. Now what? I alerted the buyer and will work with him on it. Which steps should I follow once he receives? Happy to walk him through any steps that make sense.

2. Also so many articles online that I read say the laptop will wipe once connected to the Internet, but how does it connect to the internet? Is it because on boot he'll use the guest login to connect to Wi-Fi? Can he even do that when it's activation locked?

It's not like the MacBook will recognize any networks when he gets it... And likely it will immediately start demanding a PIN because it's activation locked... So I always found e confusing because, yeah. IF IT CONNECTS TO THE INTERNET it will erase... not how does it even connect if I've activation locked it?

My current understanding is that he will get it, will connect it to the Internet (???), and it will erase. I'll remove it from my AppleID, and he'll be able to use it. Somehow though I think I have it wrong despite the online reading I've done, so I'm asking the experts here. Thanks for helping me out with this silly and early avoidable mistake.