There were more than just 2 runs that had older characters (4 total listed in your link). Also some “newer” characters had several appearances, (Emma, rogue, nightcrawler). And for a pretty good stretch the featured “newest” character was 12 characters old.
So I would say based on this data alone, they are not even sure how they want to proceed still.
Oh that’s exactly the same as my situation. Restarted when Prowler first came out, and somehow managed to keep pulling him until he hit 5/5/3 and never got around to leveling him to L209 because they skipped him.
If you run an event in PVP called Oops, All Spiders! maybe next time make sure it is only Spider characters who are in the fights, as opposed to Gritty et al… I get the Spider heroes are all boosted, but limiting characters in PVP themed events would actually make the player base a little happier. Especially if it’s an off season event. Give more variety and challenges in those non-required events. Just food for thought.
*(07/03/19) Brigby - Updated Versus events, Story events, Deadpool’s Dailies, Weekly Buffs, and added details about 4-Star Mysterio.
Brigby, why not list the 3 required 4*'s for Shield Training under Event Rules?
I just champed Green Goblin so excited to take him for a boosted spin in Webbed Wonder!
Anyone know which color should be offered for BSSM in HfH during Venom Bomb?
Don’t say green.
Edit: I’m pretty sure it was purple last time.
Also, I’m about done with this boost list. Wait, another week? 
There sure are a lot of Miles covers in rewards next week. One might start to wonder about certain things…like whether he might become a feeder…
Huh, this boost list is sticking around. I had originally intended to champ X-pool next. But considering I only have Spider-Woman champed of this boost list and it will apparently still go on another 2 weeks, I think it might be Miles’ turn instead.
Sees Spider-folks everywhere…
Well played, sir. Well played.
Wow, that’s updating things well into the future. The only thing you wouldn’t be set for on the 14th is DDQ. That’s more than ten days after when this was posted. Thumbs up.
*(07/09/19) Brigby - Updated Versus events, Story events, and Deadpool’s Dailies.
Green goblin, then BSSM, then Gambit? 3 straight oldies in a row. When is Storm going to come out and play?
They’re completely off the pattern at the moment, but technically, we had Captain America, then the new boss event, then Peter Parker, then Goblin, then Black Suit, and now Gambit, and Cap+Gambit were our 2 classics, so we should be back on pattern for Rescue and Hela and Storm next (we’re close to the end of a cycle, only Thanos, Black Panther, and Okoye who haven’t been featured in a classic slot this time around).
*(07/12/19) Brigby - Updated Versus events, Story events, Deadpool’s Dailies, and Weekly Buffs.
Bless you for including the round rewards, i know i always ask. This time all i can say is Thank you!! 
Oh, sweet! Black Cat as Round Rewards! That brings her pretty close to champable!
Yes, my 2/4/4 Black Cat is digging this indeed.
Cool we get Black Cat in Sin Six, but Thor as the 3 is a surprise, the featured character in Strange Sights, then again 2 events later?!