AAV replacement challenge...nope, just a procurement train wreck.

Keeping the AAV in service till 2030 and beyond is like asking Gulf War 1 Marines to ride into battle in LVT's from WW2.

Check this out via Forbes...

The details of how this plan emerged are complicated and depressing, because General Amos gradually came to realize that he lacked the resources to implement his vision of what the top Marine Corps ground modernization priority should look like due to congressional spending caps on military spending. Not only would the new amphibious vehicle not be able to offer the enhanced survivability and maneuverability of a planing system — it would move more slowly through the water like the existing vehicle — but it would have wheels rather than tracks, because that’s what the service could afford (tracked vehicles have traditionally been preferred for all-terrain mobility).
In effect, the lesser of two amphibious vehicles the Marines had been planning to develop became the centerpiece of near-term modernization, and the idea of replacing the existing AAV was deferred for the umpteenth time.

But wait there's more...

The larger question here, though, is whether the Marine Corps can finally firm up its plan for modernizing amphibious vehicles and make some progress on fielding new systems. As the capabilities of prospective adversaries have advanced, many observers have begun to question whether amphibious warfare has a future. Failing to field modern systems capable of safely transporting warfighters from ship to shore exacerbates concerns about the dangers involved. Thus, if the Marine Corps wants to sustain political support for its most distinctive mission, it needs to start bending metal soon.

I don't even need to see the budget to know that the Marine Corps can't afford the F-35, CH-53K, buy more MV-22's, the JLTV, upgrade the M1A1 to US Army M1A2 Tusk standards and afford the ACV.

The USMC procurement train wreck is a reality.