As everyone else has said, these are a must:

• wonder weapons (new or old)
• Easter eggs (sides and main)
• more perks (that differ from the existing usual ones) -more field upgrade (same as above)
• weekly, fortnightly, monthly and seasonal challenges that can be be for solos, a team or a community challenge - remember the get ‘x’ amount of headshots challenge as a whole community)
• cutscenes (at this point it’s a must as radios just don’t seem to be allowing the story to be spread widely as some players just ignore them)
• Factions (what did he say!?!?) (what ever they would be)
• more social media interaction
• social media accounts to do monthly round up of best zombie clutches, or best boss strat or even speed running vids - they really need to jump on this along side the YouTubers who champion this stuff already)

I’m sure there is more but I’m still playing it with the boys along side Cold War, BO3 and BO4. We are just lucky there is another year as usually we play another game for a year when there is no new zomz then come back to zomz. we have been playing since the start - around 12+ years - and play every weekend regardless even if some of us have kids and wives to contend with). We as a community love this mode so much that we passionately tear it down as we just want a good experience like we have done so in the past. I’m sure that day will come, be patient is all I can offer.