Nope, bottom three teams (8th-10th) play in the LCS Promotions (Relegation). This is true for both EU and NA. Their standing at the end of a split, determines where they start for that. 10 Place get's placed in an Elimination round against the 2nd place Challenger team from their split's playoffs. The winner of that (Match A) goes to Match B, against the 8th place LCS team. Meanwhile the 9th place LCS goes up against the 1st place Challenger Series team in Match C. The losers of matches B and C then go on to a final chance fight, Match D.
The winners of Matches B, C, and D go on to play in the next season split of the LCS, while the losers of Match A and D are seeded back down in Challenger. Tonight is Match A for NA Promos (EU already completed theirs), and will be 2nd place Challengers Team Dragon Knights (TDK) against 10th Place LCS Dignatas (DIG).
Interesting fact, a number of TDK players, are former Renegade Players before their late split roster shakeup. Additionally they were an LCS team for Summer 2015 (they were the 10th place team. and were subject to the old LCS/CS rules where 10th place team was Auto-relegated to CS)