I see no reason why they won't use the same formula as it is the best way of mitigating against any one team getting an easier/tougher group of loop fixtures.
If the same formula is used for Magic Weekend we would then play Warrington again (2nd in league table v 4th).
This season Saints, Salford and Wakefield played London twice at Ealing. They were 1st, 5th and 11th in 2018. So if done using the same exact formula then Saints, Castleford and Hull KR will play away at the promoted team twice next season.