Well, for now the connection problems are effecting how many players are on line. I can't really speak to the empty games for now because I can't log in. LOL! As for the overall trend.... previous years zup had been heavily promoting the game. He hired staff, bought adds, pressed promotions, spoke at trade shows, got deals from server hosts. Df1 was still NOT a financial success. Not. This means that even if it were possible, it would be asinine for him to try to go back to DF1.
Zup has basically said that for now he is running it more as a hobby than as a business. Players stumbling on the game in the app store still seems to bring in a steady stream of noobs. Maybe that's enough to keep the game going since the overhead is lower by not having to pay for more premium servers. Maybe it's easier to manage the game with fewer players. He has said that it is normal for games to have high points and low points and for players to move on. If you no longer enjoy it you can move along. Don't get all offended by what I'm posting here, I'm only repeating what has already been said.
Zup has been given advice by some of his peers to shut down the forum , close world chat, and basically let the game run. Zup doesn't seem to want to go that far, even though he has said how much easier it would be for him to do so. It probably wouldn't hurt Zup a bit if most of the old guard quit. Imagine coming to the game as a noob without a whole bunch of high ranked players who have been playing for years slaughtering you with expensive upper tier planes. It might not seem so futile to buy a few coins to get a mid-tier upgrade.
Spawnkillers and campers? Isn't that a problem in most combat games? Someone (Cypher 7) recently proposed a timer for once you enter enemy territory, maybe zup will give that a try... after he fixes the connection issues, lag issues, cheat codes, trolls...
Also, back in DF1 with level 31 being MORAF, there were already something like 300 players who had made it that far. Many who had made it posted about a feeling of "okay, what now?" BStranchan had quit playing almost entirely until the new higher ranks were introduced in Elite. Having the top ranks so incredibly high provides more room to rank up. I'm amazed by how many have made it to the new stratospheric rank of MORAF.
DF Elite may dry up and be gone with the wind or it might keep on as is, gradual upgrades, new features and all. It's your choice to stick around or not. You can always check back anytime to see if things have changed.