#2 Double turn
This match is a strange dynamic but the certain thing is Jinder Mahal will be walking into Houston as the heel in the match. But WrestleMania 34's planned main event is still Roman Reigns vs Brock Lesnar.
If WWE wants to have Reigns walk out of WrestleMania as a babyface, then they're going to need to get people to overwhelmingly accept him by the end of the night. If Lesnar were to walk into the main event at Mania as a huge heel, then it would be easier to pull off.
It could all happen at Survivor Series. Brock Lesnar would mercilessly beat Jinder Mahal down until the crowd starts to feel sorry for "The Modern Day Maharaja". After the referee calls for the bell, maybe Paul Heyman could jump in and try to stop "The Beast Incarnate", but he hits Heyman with a move which would be safe enough but still looks good.
In one swoop, if WWE orchestrated it properly they could change Jinder Mahal into a man people care about and Lesnar as a cruel psychopath. There would still be people cheering or booing both people but it might be an interesting way to bring Brock Lesnar to the dance at WrestleMania as a heel.
Besides, Jinder Mahal can be a pretty personable guy with a great sense of humour if WWE would let "The Modern Day Maharaja" be a more likeable character. His work with 3MB illustrated that fact well.