I am curious about this. I’m sitting on what equates to 17 LT that i have been concerned about opening. But with the champion mechanic, i do intend to go to town on my 3 
s. Should i still be concerned about getting 5
s anymore?
Maybe it’s just me, but I’m seeing no relation at all between the two.
Well, players would essentially be tasked with fixing an inherent flaw in the game on their own, potentially involving the further expenditure of money to make the game playable again, sooo… lol
DBC
With regard to 5*'s especially, champions will have very little impact on whether or not scaling is needed.
If you only have 94’s, and a 5* screwed your scaling, it will still pretty much screw them at 144. They don’t get that much more powerful.
…I am actually wondering the opposite. It almost seems like it makes the need to fix scaling more important, not less. The incremental power gain in level is nowhere near the power gain of PVE goons at similar levels.
I started drawing 5s when I was capping my 3s at 106 to play nice with my 94 2s. I then pushed all (possible) 3s to 120 and sat there collecting covers and ISO, and then pushed a small group of decent 3*s to 166. My experience was:
106 max: can’t play. Need to join at last minute and hope for placement rewards to progress. (+DDQ of course)
120 max: still can’t play PvP due to match making. PvE t100 possible but still mostly sniping brackets. I could complete a sweep in PvE most of the time, but it would eat all my health packs and grinding was not possible.
166 max: can start to play again in both PvE and PvP. (although skipping 5-10 times to find a playable match in PvP)
This all relates to how scaling was impacting me thanks to 2 5s at 255 relative to the rest of my roster (including boosts). I don’t think championing itself really matters, but if it motivates you to raise 3s to 166, then in my opinion you’ll be OK keeping your 5s (or taking the “risk” of drawing a 5).
Who knows?
Apparently there is a bug with boosts to championed chars, but we don’t know if they’re weaker than intended or whatever, because patch notes are so 2014.
Would be nice to see some data on how Champions scale with levels directly from the devs, but it looks like they decided it’s much more fun to let the community figure it out by itself.
IN THEIR MIND? Yes. Of course.
I suspect this is the new formula as well. Game devs basically did a wholesale nerf on everyone’s rosters. 
Champions do not negate the need to fix scaling at all, at the absolute minimum they have to include more characters in the scaling calculation and should be taking base levels rather than boosted levels too as it is idiotic that a ‘boosted’ character should end up making the game harder.
Taking my own account (evenly leveled prior to champions forcing me to push some forward) in the latest event, changing scaling from highest 3 to highest 10 characters would lower my average by about 20 and would be far more representative of my usable roster.