You may want to inform your lawyers that promises made in advertising is legally binding in some countries, such as Australia.

The "Plus" and higher tiers are advertised as "The latest models" but if that's not true any more then Open AI is opening themselves to investigations from organisations like: https://www.accc.gov.au/

Promising "X" for $Y to everyone and then delivering "X" only to the "chosen few" at the detriment of others opens you up to lawsuits because then your product advertisement is a lie.

For a comparison, imagine a telco selling "100 Mbps for $20/mo" and then throttling the connection for customers that aren't currently favoured by the Trump administration!