You guys heard of the Rabiah scale?
Similar to the Storm scale, it's a ranking on how likely we are to revisit a plane in a standard-legal set. 1 is super likely and 10 is nigh-impossible. It hasn't been updated in a while, but here are the rankings.
1: Dominaria. Innistrad, Ravnica. The last update to this scale was right before the
release of Guilds of Ravnica. We are most-definitely going back to these planes.
2: Zendikar.3: Theros.4: Ixalan, Tarkir.5: Alara, Amonkhet, Kaladesh, Lorwyn/Shadowmoor, New Phyrexia/Mirrodin.6: Fiora (Conspiracy), Regatha (Core sets), Vryn (Magic Origins).7: Shandalar (Core 2014), Kamigawa, Kylem (Battlebond).8: Segovia (The Hippodrome). Plane where everything is much smaller, and when planeswalkers come here, they
shrink down... so what's the point?
9: Ulgrotha (Homelands), Serra's Realm (Urza block), Rath (Weatherlight Saga), Phyrexia (Weatherlight Saga). Because these planes have been destroyed, we likely won't go back.
Mercadia. A backwards world (goblins are smart, mountains are upside-down) is unsurprisingly hard to design.
10: Rabiah (Arabian Knights). Due to intellectual property issues, we will likely never see Rabiah, but we might see another Arabic/Persian styled set.
Bablovia (Unstable). Because this is the world of Unstable, we won't see it appearing in standard.