The truth is that major cloud providers such as Amazon AWS have begun to charge [more] for static, routed IPv4 addresses.
Last I checked (a few years ago, I suppose), AWS APIs were incapable of using IPv6 internally, so a VPC still needed to dual-stack it in order to use AWS cloud features. That may have changed by now.
Says you need to have an AWS NAT for that to work. And AFAIK, setting up a NAT requires an ipv4 elastic ip.
And it makes since that AWS would want customers to have their own IP for NAT64, so that if one customer does something to get the ip address blocklisted it doesn't impact other customers.
If they had increased prices in 2022 (or at least announced in 2022), then I could see some kind of correlation, but give it was 1.5-2 years after, I doubt there is a connection.
> i would expect aws needs a year or two from when they decide to charge for something new just to work out the details
The price had already dropped, and was continuing to fall, when they announced the change, so if rising acquisition cost was the primary reason for adding the IPv4 charge, it had already went away.
I think AWS has looked at a utilization graph and sees a time their current pool is get used up at current rates and doesn't want to go through the hassle of acquiring more IPv4 addresses, regardless of cost (even if it is "cheap").
I also think that they have statistic for their www.Amazon.com storefront, and maybe are seeing a good proportion from IPv6 and so figure that there's a 'critical mass' (especially mobile).
Last I checked (a few years ago, I suppose), AWS APIs were incapable of using IPv6 internally, so a VPC still needed to dual-stack it in order to use AWS cloud features. That may have changed by now.