I know I am old, but don’t understand why providers with good reviews would change names?

I suspect a new group being formed with new location. Previous management doesn't want to give them their email access so they have to create new identities. It's well known these girls don't have access to their provider emails.

No new ownership. This is how this group operates. They change names and locations every so often to cover up their tracks, or so I’ve been told. If you are in good standing, and want to see your regular just reach out and ask who x girl is now and you’d like to book with her.  

Over the years this subject has come up when I am with a woman in the hobby. They change info sometimes due to one reason. Stalking. It doesn't take but one guy to unnerve them so they change their on- line ID.  

I don't know about them, but this has been some grifting problem for decades. You get one moron that sees a local or visiting lady, and then he spreads her location all over the frickin' place.

Its done to keep people guessing, it solves the issue of a stale relationship - simply drums up new demand due to curiosity

I've had the same problem, wanting to visit a lady I like a lot who I've seen previously.  But when I send to the "old" email address, I don't get a response because it's been discontinued or no longer followed by the agency.  
    My problem is, how do I know the provider's new name and new email address?    The ad on MNE changes, so the search feature is of no use.  And the pics often change, so it's often useless to look via pics on MNE.  

You are emailing the agency so just ask them .
Ask who X is now and if available- if not who would they have that would be.
This should work if you are in good standing.

If a girl gets crap reviews then you just rename her and take new photos and she has a new lease on life

I agree that sometimes name changes are made because a provider has a bad record of reviews.  

Exactly, just like Fakebook, they rebrand it & is now called Meta

Reasons I have heard in my 15+ years:  
Stalking is number one ,
bored with the name
found something that feels more personal
wants to rebrand with new services,  
wants to rebrand because they're moving passed their first mistakes and want to do it differently next time around  
Wants to pull in different clientele,  names do matter  
Had issues with past "boss"  
Had past issues with other providers in the industry
Word got out about their name and someone they knew found out.  

Would have never thought of many of these but all legit reasons.  Thanks for the incite Rain.