Discovery API is now moving to Enterprise+ Only?

Our Enterprise Select subscription is now 'legacy' and is being deprecated by July 2027.
A sales rep has been in touch to offer Enterprise+ at a discounted rate which still ends up being £9 more expensive PU/PM than Enterprise Select.

I don't see a use case for Enterprise Plus, however, on Slack's new plans, Enterprise+ is the only plan that now supports Discovery API which is required for Global Relay Archive for Slack integrations.

So that being now the main caveat, are we now stuck paying an extra ~£7200 per year over the Business+ plan (which I'd ideally shift to) because of Discovery API now being a 'premium' feature?