So I can't speak for everything regarding Old School vs Vintage, but I've found the breakneck pace with which people demand change in Vintage to be extremely harmful to paper Vintage. Since MODO moves so much faster, people are tired of a new metagame in a week and begin to loudly proclaim on social media and wherever else that the format "sucks" and that we need a change and X should be restricted and whatever else.
On the flip side, we used to have one Vintage event every few months. When you have zero investment in a format that you're sure is going to change by the time the next event comes around, it's really not something you want to get into. Add onto the fact that people loudly proclaim the format isn't fun when you've barely begun to even play it, and it's not hard to see that there is not much desire to play. We no longer have Vintage events every few months.
Old School, on the other hand, fulfils this desire extremely well. This is why I don't believe proxies will do much to change anything since the cards clearly exist. The desire to play Vintage as it currently is just isn't compatible with what players on MTGO want.
I think some proxies is absolutely necessary on any level to get new blood into the format. However, I've found that 100% proxy events tend to create not much care or investment in the format. A potential player would come to play hoping to spike a Vintage event for the EV and have 60 basic plains sharpied with the latest deck that won a MODO challenge. There would be very little investment in the format itself for such a player, and in which case it is not growing the format at all. I'm not sure that's the sort of event I'd be interested in going to.
To clarify, I do think proxies are needed as I wouldn't have gotten into Vintage without it. But limited proxies are sufficient. Anywhere to 10-15 proxies sound fine to me.
It saddens me, actually, that WotC spends most of its time cranking out dross like Theros and Ixalan and Battle for Zendikar when it is capable of designing War for the Spark and Modern Horizons instead.
While I do agree with you, this is most certainly because their aim is to cater to a wider variety of players. Vintage players tend to like powerful sets such as War of the Spark, but if you look into the feedback the limited play of WAR is getting, it isn't very positive.
So I'll take the fun and broken sets as and when they come.
A white or green Ancestral would be nice.
I don't think this would (should?) happen because it would be a blatant disregard of the colour pie. Now, if there was a different way of gaining card advantage for W or G, certainly. But that wouldn't need to care about the reserved list necessarily, based on what sort of effect it would be doing.
Or I suppose if we ever get Planar Chaos 2, but my understanding is this is highly unlikely.
I prefer the wild-west variety. I think FoW in the other 4 colors would shift vintage to that.
No, it really won't. Not unless you also print Ancestral Recall, Time Walk, Tinker, Treasure Cruise, etc in all other colours. Once again, Vintage is blue-centric because the most powerful cards ever printed happen to be blue. Until that changes (if it ever does), it will always remain blue-centric.