Short version; you're just screwed. With all of five days left before season's end, you're just gonna have to do better next year.
As KVbqbFsC8e pointed out, this isn't new. It was first implemented in 2017 with the Honor System rework, and it's been consistently applied in the years after (2018, 2019), so it should be well-known by this point that Honor Level 2 is a prerequisite for End of Season rewards.
And the principle concept behind it has been around even before the Honor System rework; before Honor 2.0, if you got punished at the tail end of the year, or otherwise had an active punishment at the cutoff date (which was separate from the actual end of the season, about a month or so back), you'd lose Ranked reward eligibility.
And I've been playing the game for a good 4-5~ years now, and it has been a thing since I started playing, doubtless even before that. You can climb Ranked all year long, but if you get punished at the tail end of the season, that climb is effectively meaningless.
The only thing the Honor System did was streamlined it. It's tied to the actual end of the season instead of a behavioral cutoff date a month or so before, and players who are consistently dishonorable can be disqualified even before the season nears its end.
You may think it's overkill, but it's a fair expectation: A competitive mode comes with the expectation of sportsmanlike behavior. Display unsportsmanlike behavior, and you don't get rewards for the competitive mode.