Possible
Likely?
That's all up in the air. Each successive sequel so far changes the weapon mechanics so much it's impossible to predict.
The pistols are a prime example.
1. Powerful with scope
2. Rapid fire with less power
3. Slower fire with moderate power
4(odst). No power but scope
There is a distinct lack of consistancy from volume to volume, even on items that are the crowd favorite.
So far, the best recovery from a disorienting experience is the return of the rocket launcher to near CE standards with Halo 3.
And given the new abilities with the 360, even after release, Halo 3 had issues with balance and didn't settle after release for a good while, it was like playing a beta still.
You'd think by the 3rd time around they'd have a stable base...yet with ODST the same radical changes happened with weaponry(mechanics are understandable as it's a normal human).
I don't expect that part of Reach to be any better than Halo 3 was at first. I do expect to see things I like nerfed or missing entirely, some new and pointless things, and some of the least used weapons completely untouched.
In short, you should be a pessimist. Expect the worst and you're never let down. And if it ends up being a great game on release, your surprise and joy is that much more.