Yeah, Richmond just isn't happening. There isn't a realistic scenario that would make that a possibility anytime soon. And other places (Harrisburg, Pawtucket) are even less likely.
Hate to say it, but 2020 is going to be a lot like 2018. Once you get sucked into the PCL, it's hard to get out (ask the Mets, Marlins and Blue Jays...). I know we look at the chart and see all those agreements expiring in 2020, but most will be renewed in the next two years. And with the Marlins' team getting moved to Wichita, they may become more aggressive in their pursuit of an IL team, so more competition.
We can dream on places like Charlotte and Durham, but I don't think any are very realistic. Charlotte was tops in attendance this year. Why would they change things? Durham just won yet another IL championship. Tampa's been very, very, very good to them. Maybe things are 'meh' enough in Indy where they don't bring the Pirates back? But Rochester is still likely to be the best bet to get back into the IL next time around. The Nats should buy a bunch of season tickets in Rochester and pay fans to go to every home game decked out head to toe in Nationals gear. Make it look like there's a loyal Washington fan base there. I'm kidding, but desperate times...
And yep, you want to put an IL AAA team in a city that doesn't currently have one? Then start rooting for Oakland and Tampa to get their new parks. Once that happens, MLB expansion efforts will start to gain steam. With new MLB teams comes new MiLB teams. I think that's when a place like Richmond for AAA becomes more realistic (Richmond and Jacksonville make the most sense, imo), and you'd hope to see ownership make a push to be involved.