That was a supplier, when told we will not buy non IPv6 services and kit. I won't say who said this, but this is a sad state of affairs.
As I try to explain:-
What makes you think this is about CPs having IPv4 space?
(a) ISPs (LIRs) forecast 6 months when requesting from RIPE, so they should not have more than 6 months left when RIPE run out. RIPE expect to run out in months, not years. By the end of the year we would expect CPs to be running out, or at the least seriously limiting how they issue IPv4.
(b) Right now there are endpoints on the Internet which our customers might want to access and are IPv6 only. It does not matter how many IPv4 addresses I have, if I do not provide IPv6 routing to my customer they cannot access all of the Internet.
The second point is relevant here - the Internet is not just IPv4. From now on we will see increasing numbers of cases where an endpoint is IPv6 only. It may be specific uses of services in specific networks initially, but eventually it will be proper public web sites and mail servers and the like. It only takes one endpoint to be IPv6-only and our customer needing to access it, and you have a problem, now!
P.S. Thanks to Simon on irc for finding an example http://video6.ustc.edu.cn/
Without IPv6 you cannot get to that and the apparent IPv4 version has no routing and anyway it links to pages like http://[2001:da8:d800::88]/firstname.lastname@example.org