eh its really to make her "relevant" well not really.
She's only there to complete the whole Team 7 BS anyways. same with kakashi.
In any case, your argument about her releasing chakra when hitting is null.
Any NORMAL chakra released is, as you say, ineffective against Kaguya.
But she still punched her. Now you may argue that it was not a normal taijutsu punch as her strength is backed by chakra.
Again, it's to make her relevant.
While others get nerfed to be relevant or to get them to fit to the story, Sakura and any other useless female char gets a buff.
So just blame Kishi's crappy writing. The only one that remained TRULY useful and relevant females are Ino, Tsunade, and Mizukage anyways.
Even Kaguya is trash. She was this all powerful being then gets nerfed. This medic ninja gets buffed to the point she can touch a goddess.
I don't even know why there's a discussion about whether or not Sakura deserves glory since Kaguya is written poorly and therefore all the threads regarding feats during the fight is moot.