Satire is best served hot.
In my opinion, you should try to publish it as soon as it's ready.
If you find an agent or a publishing company interested in the novel they'll give you their (probably very valid) inputs on how to market it and when it would be best to publish it. Chances are that they will have good insights on this, since it's their line of work.
But from your side of things, I don't see how waiting could be beneficial. You're not writing an essay, you're writing satire; and satire has to kick a punch. A lot of people will still remember today's political climate in three years (because, unless the Earth doesn't gets blown in pieces, our memory isn't that short).
But yes: it will be less relevant. If the problems you're going to point out with your satire are getting better, or are solved, you'd be late. If they are worsening, you would still be late, and maybe your book will lack depth. And of course, in any given time, things change, what's relevant now won't be relevant forever, yada yada.
So, since you stated that you want to raise awareness, I'd say don't wait. Take the time you need, but no more. If you happen to publish it late, it will still be value (probably in retrospective) as most books have value to us regardless of age, but there is no point in purposedly wait.