"Get to a conclusion" is comprehensible but not idiomatic.
The basic reason is that "get to" constructions have two meanings:
- the meaning of arrive or come to a place.
- the meaning of arriving in time. In this usage, it can be a marker of tense as in for instance, "I am going to be 6 feet tall when I grow up"
So for instance,
Just wait 'til I get to the bottom of this.
= I will get to the bottom of this and then something will happen.
For a conclusion, "get to the conclusion" could mean either:
- I read from top to bottom of a one page paper. At the bottom, I "got to the conclusion" in one sense.
- the argument brings us / they to the conclusion. In other words, the argument or data succeed in producing the conclusion.
As such, it's much clearer to avoid this sort of construction with respect to conclusions.
Moreover, even when comprehensible, this sort of use of "got" is not academic (and as such doesn't agree with "conclusion").