Based on where I think the Strahwats are right now power wise, if the admirals aren’t the immediate opponents in the arc after Wano, and we still have another saga before we get to them, then they’re emperor level.
I don't think the admirals will serve as any specific arc opponents outside of the final arc.
Imo, what is next is Vegapunk/Revolutionary Army stuff and addressing Kuma/Bonney. There is a huge plotline to be had there that I think isn't exactly "final arc" centric. Plus it looks like the Revolutionary Army may end up becoming "complete" before they tackle the CDs/CP-0.
It's pretty clear that that RA's have 6 commanders, 1 for each blue, Ivankov for GL, and probably Kuma was the New World commander. Sabo is the #2, and Dragon is the actual leader.
We have that, plus probably Elbaf to deal with first. The arcs don't have to be long or contain fights for each Strawhat member, but who knows how those are handled. Is the SSG an arc villain group or final war? Is Loki an arc villain or ally? Where do Bonney and Urouge fall into the story before Laugh Tale? Will the Underworld play bigger roles? Impel Down escapees?
Things like that imo before Admirals/Akainu, and even those I feel like will be defeated before the Gorosei or Blackbeard or maybe even Shanks.