Dain's roster move may come as soon as tomorrow's NXT TV tapings from Full Sail University. Dave Meltzer noted on F4Wonline.com that Dain is headed back to the black & yellow brand after what happened to SAnitY in the 2019 WWE Superstar Shakeup.
As we've noted, SAnitY leader Eric Young was sent to RAW from SmackDown with no mention of SAnitY. Alexander Wolfe recently made his NXT UK debut and will be making his new home there. Dain is headed back to the main NXT brand from SmackDown.
WWE has not officially announced a brand for Nikki Cross, who is married to Dain, but Meltzer notes that WWE has confirmed that she will be on RAW. There's no word yet on when Cross will make her return to the RAW storylines.
SAnitY spent some time together in NXT before being called up to the blue brand in June 2018. They have rarely been used since getting called up, having only made sporadic appearances on SmackDown Live.