The suit shown is basically his from Black Panther, black and gold with the long gold fingernails.
If it were Shuri I'd expect a different colour palette for Marvel to sell toys, in the comics her Black Panther costume is black with a purple cape. Also T'Challa's mum says 'I've lost my entire family' which hints that Shuri isn't around either otherwise it'd be a weird thing to say, and there's a shot of Shuri looking like she's in a different plane - maybe trying to get Killmonger back which would explain why they brought in Ironheart as the 'tech' person in Wakanda to fill that role during this movie as well as setting up Amor Wars. They needed T'Challas body to bring him back from the ancestral plane in BP1 and at the end of BP1 Killmonger requested to be buried in the ocean, so the massive ship going out into the sea might be an attempt to reclaim his body from Namor who would have it.
So while that makes sense to me, a con here is it feels a bit weird setting a precedent that if they have the power to bring people back from the dead that the Wakandans would choose Killmonger and not T'Challa. Obviously outside of the movies we know why, but that would be reason enough for me to avoid that plot line completely because it just doesn't make any sense why they'd choose him. I can't think of a conceivable way that a director can explain why in the movie the Wakandans decided to resurrect the murdering cousin who overthrew them and ruled tyrannically for a bit instead of the just and fair king they all love.