Not exactly. It's true that they are (mostly) not found in the same block as other (alphabetic, numeric, punctuation etc.) characters. But there is no single emoji block, which makes it hard to write regular expressions to search for emoji, unless you are using a regex language that allows reference to Unicode properties (like Perl, or the Python3 regex library, not to be confused with the more commonly used re library).

I guess, literally, all the flag glyphs are very political.

I think people mostly mean "i disagree with it politically" when they say something is "political" though. If they disagree with it politically, then it's "political".

Fifteen skincolor variants and pregnant men.

Let me introduce 2 websites that can answer your questions : Google and Wikipedia. The former allow you to search website on the called web platform, and the latter is an online collaborative encyclopedia.

By using those two websites, you can easily find the definition of a writing system, which is "[...] a method of visually representing verbal communication" and reflect on the fact that since emoji aren't used to encode an oral message, they don't form a writing system.