Does Malphite ult NEED to cross walls (after the Vanguard update)?

I know dashes in this game are typically allowed to go over walls if they are long enough (with some exceptions), but I wonder if that's absolutely necessary for the big gapclosers on Vanguards. For doing the Vanguard thing of barreling into the enemy team to initiate a fight, completely ignoring barriers seems a little less thematic and leads to more of an "I want to stealthily flank and assassinate an out of position target" pattern than "I want to boldy charge forward and lead my team into a fight." So maybe a good way to sharpen the niche of Malphite and make space in the Vanguard world for him alongside the others would be to change his ult so that it is really good at initiating across open ground instead of just really good at initiating always in every situation.

Sion is on the polar opposite end of the spectrum where he announces his charge to everyone on the map, takes some time to warm up his speed for the doom train, and can't pass through walls or even other champions and I think people generally believe this still feels pretty awesome. He has those weaknesses for the ult but it counteracts the strengths of the massive range making him nearly a global threat, the powerful cc it applies on targets hit, and how capable Sion is of being a follow-up threat with the rest of his kit.

I don't think all the Vanguards need to have their charge as telegraphed and counterplay-laden as Sion's, but maybe those telegraphs and forms of counterplay should be the norm for Vanguards and when someone like Zac (because Zac's jump is really fun and iconic and I don't think it should be changed) can hop huge distances over walls and champs with little warning that should be seen as his 'thing' that you would pick him for over other Vanguards.