I don't think thats true, Mine have standard MCC +4 which should be replaceable via the usual methods.

Any grips can be replaced. Maybe you can't find the stock grip again, but there are better grips than stock you can purchase.

If you have the Titleist branded tour velvet, they aren’t always available even with new clubs direct from Titleist. My last couple of purchases have come as Golf Pride versions. Grips are more readily available. Good time to research other options.

Sounds to me like someone wants to get into your pockets, DEEP. You can replace any grip any time you need to. You can take your clubs to any golf shop and have them replaced or purchase the grips you choose and do it yourself. I let my Titleist account repair shop do it for me. Am retired and earned that luxury. That story is pure BS and do not fall for it. Might be a misunderstanding also. Might have meant that those grips not available and need to buy all new grips. You DO NOT NEED NEW CLUBS, pal. Aussie, Aussie, Aussie.

Never heard of any grip that cannot be replaced
Go into any pga shop here and the selection is huge

Imagine how many clubs would be discarded if it couldn't be regripped

You cannot buy from Titleist the iron grips directly, you would just need to visit your local golf store that sells golf grips and purchase them there. I have never heard Titleist say you need to purchase a new iron just for a new grip...

Basically, I think there is a communication gap in this process... IMHO

Cheers!