Look BF1 has its issues that need to be fixed but you are integrating BF4 with BF1 so players can jump between both.... why exactly??
Do you think a year from now people will still use that feature or play BF4.. a game that has been all but abandoned. If you are for real about keeping BF4 around something's need to be done to BF4 to keep it relivent so players don't go to COD or other tittles when they get board of BF1.. I will list a short list of what needs to be done to refresh BF4 and keep both games alive and well.
map rotation on official servers and DLC packs. Unlock premium for everyone for FREE and have a variety of official servers running all the DLC maps. If you look at the browser other then a few custom servers they are all running vanilla maps. Not good when you play the same few maps all the time and there are a lot more you could play.
prestige option and exclusive prestige content. Prestige should reset all you in game items as if you where lvl 1. There should be exclusive prestige lvl emblems, gun skins, dog tags, and it should all be all be based off progression with a class and particular weapon. This would refresh the game along with new map rotations and make it feel like a NEW beginning.
graphics engine upgrade to the BF1 frostbite engine and reoptimization and each platform. I play PC and Xbox. BF4 vs BF1 on Xbox is a pretty decent difference. 600p vs 720p is noticeable. Reoptimization should be preformed and experience enhanced to make it feel fresh.
premium supply drops or creates added to BF4. Add new unlockable that are independent from current supply drops. One premium supply drop is given every two ranks achieved in prestige 1 and the contain new player outfit skins, new longer lasting XP boosts, grenade skins (add the smile face from BC, make them pink, crazy stuff), vehicle specific skins, weapon sacrifice skins that are awesome! But you have to reach that rank to get. Give players stuff to work for. Cool cosmetics and think people really want.
more UI upgrades, it needs to be the exact same as BF1. It still contains elements of the old UI. Transition completely to the new UI.
Mew load screen images, fullfill a all new experience visually and upgrade the quality of the load screen as well as the after round menu. Make it look more advanced for 2017.
BF3 DLC maps. There where some awesome maps in the DLC packs for BF3. If you release a content upgrade to being players back containing 1 map from all the DLC packs (most requested/popular) and add them to the game a lot of people would want to come back for all this and the people still playing would be blown away.
One last recommendation is to make the game $14.99 w/ premium included. At this point it's about market share. This would be the cheapest, most fun and more then likely most played game on all platforms. Rivaled only by BF1 and the newest popular games. Not to mention millions more would buy the game world wide all the time for years to come.
We are a couple years from another Bf game (hope is alive for BC3) so you would at that point have three different bit awesome interconnected games BF4, BF1 and BC3? Price points at 14.99, 29.99, and 59.99. All supported and refined. It's at that time support for BF4 could start to drop off. If you abandoned your games like CoD does you will end up looking like coda 50% sales drop off year to year.
Also This all builds up to the current release of the PS4 Pro and the soon to be released XB Scorpio. BF4 could be the go to game cause of quality, cost and replability on all new system cause of just how amazing it looks, plays and costs. This will also get more people into battlefield and increase sales margins of the new BF title currently available. Look what valve and steam do with CSGO.. a game that costs 14.99.
Please countine to make this game better DICE. Evolve this from 2013 to 2017. BF4 is to good to die. It can still make a fortune as long as the price is right and the game is refreshed.
Let the trolling begin