I mean it's a dumb pun but it's not like you have to use it.

: Dude-Bro Spartans high-fiving?

That was only in the Halo 5 beta, and they took out that and all the other major animations.
What they should have done is toned it down, because now everyone just walks a bit, shoulders their weapons, and stares at nothing, it feels pointless.
If they'd taken out high-fiving or made it rare, taken out that shoulder-rolling movement, taken out some of the pointing, and toned down the rest, it would make for something that's visually interesting without putting too much character onto a player who may not agree with that character. They also could have had your selected stance that people see in your profile apply to end-of-game views. They could have had an ability to turn it off locally and/or on a map or gametype basis. At worst they could've taken out the posing altogether, if they weren't going to make it look good.