So the new pvp template system is pretty decent, the base issues such responsiveness are still there, sadly, but overall it's better.
That being said, there are some pretty glaring issues.
Frontlines with the current pacing are just not meant to be in 72 player format. The maps are too small, the damage relative to hp pools is too high. It is unfeasible to play a melee, range jobs are reduced to doing pot shots on those that stray too far from the zerg, and there's just not much fun to be had for anyone. I believe lowering the format to 8 players per faction will alleviate this problem, atleast a little bit. Multiple objectives will force the party to split and individual participation will actually matter. Also, it would be a really great idea to award an XP item at the end of the match so that you can play a job that is actually needed, instead of frantically suiciding towards the end of the match in order to swap to a job you want the xp on.
The Feast. Where to begin? The changes to the feast, are quite frankly, awful. I bought stormblood with the expectation that I would be able to competitively pvp with friends. The light party feast removal is definitely a deal breaker for me, and I can't really see myself continuing with this game if season 5 launches the way it is. My suggestion is this; Solo Q blows, it's not really competitive for a plethora of reasons that range from poor server responsiveness to the fact that you can't really communicate in any meaningful fashion. Make Solo Q, at minimum a duo, or better yet, allow up to 4 people to que. The pvp community will likely carry the burden and form some sort of discord for competitive players to find missing members.
Rewards:
More glamour options. Need way way way more glamour. It wouldn't hurt to be able to buy things like ventures and similar stuff with wolf marks either.
Instead of receiving things like the commander's set from achievements, have each win or whatnot award a totem of some kind that you can exchange for items that are available from achievements, or keep it simple and allow them to be bought with wolf marks. There's just no real reliable way to work towards the things that you actually want - and that needs to be rectified.
You can increase participation in the feast by offering more end of season rewards to the non top 100 tiers, that single ring/earring doesn't really motivate anyone.