Is it possible/convenient to reply to the conference PCs regarding the meta-review result of a paper? I received the reviews related to my recently submitted conference paper and it is selected as a poster, and there is no rebuttal phase provided. So they do not expect the authors to reply the PCs regarding the results.

However, after reading the reviewers comments clearly (4-5 times) and considering all of them i noticed the following:

1- One of them totally didn't get the main purpose and the domain of the paper and held a strong opposition against it.

2- The 2 Others were happy about the novelty and the results, but one of them asked for comparing to other methods (which i believe they are not applicable to my studied problem), and more analysis (which i already did in the paper and he may have missed it)

So if i had the chance to send a rebuttal letter i definitely would have taken that to send a sound, well-reasoned counterargument (but polite) regarding the above points. 

But i'm afraid doing so could be considered inconvenient and even be harmful (leading to a rejection)!
I assume that the committee has also seen the reviews and hasn't objected to them. At least a subset of the committee has likely looked. Presumably they agree with the decision. 

You can communicate with them and ask for a new review, of course, but I think you are not likely to get it. They will most likely want to follow the established procedures which, as you say, don't anticipate a rebuttal. Conferences also have time constraints and the submission/review schedule feeds in to other things that also have time constraints. They are also pretty likely to trust their reviewers. My experience with annual conferences is that the set of reviewers is fairly stable and committees also overlap from year to year. 

On the other hand, I also doubt that they would withdraw the acceptance as a poster as long as you don't come across as abusive or insulting.