The Dims didn't like how the Alabama Republicans drew up the new districts, of course yelling racism over & over. A lower federal court tried to block Alabama from using the new map, saying it helps Republicans win too much and is racist and blah blah blah. Part of the Dims' strategy was to throw chaos into the upcoming election by keeping it tied up in courts and many people in Alabama not even knowing what district they're in or who's running in that district until right before the election. So Alabama asked SCOTUS to intervene and at least let the new map stay in place long enough for the upcoming election -- and SCOTUS just now gave Alabama the thumbs up to do so.
This doesn't necessarily undermine the Dims' attempts to stop the new districts from being in place for the elections after that. But IMHO the Dims will be hard pressed to make the case that the new maps is racist/cheating/whatever-ism-they-can-think-of enough to get the new district map thrown out for future elections now that SCOTUS has given its approval for the 2022 election.
So at this time, things can stay as they are since we're late in the cycle, BUT Kavanaugh did not rule out changes down the road as this injunction says nothing about the merits of the case itself.
From my source (a newsy email from WVNN radio, so no link):
"However, Justice Brett Kavanaugh made it clear that this ruling isn’t completely final, only that the order must be blocked for now since the primary election is set to be held on May 24. Kavanaugh wrote, “When an election is close at hand, the rules of the road must be clear and settled.” He also said that this “stay order is not a ruling on the merits, but simply stays the District Court’s injunction pending a ruling on the merits.”