While Poeltl absolutely shouldn't be treated as untouchable and while his long-term fit with Scottie is questionable due to his lack of range, his absence is not going to be the difference maker in getting into getting some of the best odds of a Top 4 pick in what may be a historic draft on a team that's likely to be sub-0.500 with or without him.
The Raptors were bad without Poeltl last season but it's commonly ignored that they were also without Scottie Barnes during that same stretch, not to mention both RJ Barrett and Immanuel Quickley were out due to their own respective family tragedies. He certainly makes the Raptors better but by how much is not as clear cut as lookin at their win/loss record with/out him.
If you're trading Jakob Poeltl, it should be because you got a stupid good offer from a desperate team rather than hoping for slightly improved lottery odds. Anyone who's seen the Pistons drop down in back-to-back-to-back drafts to 5th can tell you that that it's called the lottery for a reason: Sometimes you win it big (Getting number 1 in 2021's lottery and drafting Cade) and sometimes you drop from where you were expected to go in 3 consecutive drafts.
There are no guarantees in the lottery, something the Raptors should be keenly familiar with given they lost out on their own pick in this year's draft due to bad lottery luck while simultaneously jumping up from 7th to 4th in 2021 to draft Scottie Barnes. Just as the draft itself is a crapshoot, so too is the lottery that determines who gets to draft where.
Hell, if we want to extend this out to look at the Raptors general history with the lottery, they've dropped down far more than they've jumped up. In terms of major leaps i.e. jumping up more than 1 spot, getting 1st overall in 2006 while having the 5th best odds and 4th overall in 2021 with the 7th represent the exception rather than the rule.

They stayed put in 2013 & 2012 for those wondering (They weren't in the lottery again until 2021 unless you want to count that Knicks pick which became Jakob Poeltl).
Jakob Poeltl is a known talent and he's valuable for what he brings as a defender, interior presence and an underrated passing big man. He's far from untouchable, but he's also not someone you just trade for the sake of making your team worse in his absence for the sake of what can be best described as minimal gain in this year's lottery.