FVF reductions, branding, individual category menus, and additional marketing tools are not irrelevant. 

eBay don't need to give away free listings to get people to switch, not when they already have "switch or GTFO". 

They also have a history of increasing free listings, not reducing them. 'Member when a basic store only gave you 200 free listings, and featured only gave you 500? Then in 2017, they tripled that? Pepperidge Farm remembers. 😆

ETA: For the record, I'm not saying eBay would never reduce the number of free listings, just that 250K is an odd number to dangle as an enticement in order to "ensare" people when it is exponentially higher than the average seller would ever list, and if they ever did reduce them, I doubt it would be to below pre-MP levels.