Apparently it survived the ordeal and fought alongside Godzilla and the Monster Island Crew in 1999.
...No, it died at the end of SoG. Kumonga isn't the only monster magically resurrected for DAM. Just look at Baragon, Manda, Anguirus, Gorosaurus and Varan. They all died at in their original appearances, yet are there in DAM. I think it's safe to assume that these are either entirely different creatures, or Toho magically revived them just to put them in the film.
Seriously, if being set on fire didn't kill Kumonga, then being buried in god knows how much snow would have done the job.
Kumunga effortlessly tackled Godzilla to the ground
...So what? It's not like that'll help out here at all. King Ghidorah weighs way more than Godzilla, so I highly doubt that tackling King Ghidorah would do anything. On top of that, tackling King Ghidorah is just an incredibly stupid idea unless you have regeneration of some kind. Kumonga is screwed if it decides to tackle King Ghidorah.
It also has great aim with its stinger and can wrap up prey in seconds with its webbing.
The stinger only comes into play when it's target is incredibly close, which will not happen in this fight. As for the webbing being able to "wrap up prey in seconds"...um...no. Stupid and small creatures, sure. But giant-ass space dragons that can shot three gravity bolts at once, hell no. It would take a long time for Kumonga's webs to start slowing down King Ghidorah.
Also he spams his Gravity Beams, although more often then not they miss outright.
King Ghidorah almost always hits his target in GTTHM, IotAM and DAM. King Ghidorah just fires wildly when he doesn't have any particular target.
And here's the kicker, the one flaw that seals his fate, when getting shot with webbing Ghidorah becomes completely helpless. When Mothra began spraying the webbing at Ghidorah all it could do was flail helplessly until Godzilla threw it down the mountain.
...You do realize that the only reason Ghidorah was helpless, was because Godzilla was holding Ghidorah back, and Mothra was hidden by Rodan? As in, he was in a spot where he couldn't stop the source of the webbing, because it was hidden from him and there was another monster holding him by his tails.
Too bad that won't be the case here. There is nothing in this fight that can hold Ghidorah back like Godzilla did in GTTHM, and there's no way that Kumonga can be hidden from Ghidorah. Kumonga is pretty damn big (at least in width), so that thing ain't hiding.
Kumunga likes to spam its webbing and that will deter Ghidorah.
The only thing that Kumgona's webbing will do is piss off Ghidorah, and cause a rain of Gravity Bolts the likes of which he has never seen.
Ghidorah will become ensnared in Kumunga's webbing and flail helplessly like it did in GTTHM.
...That would only happen if Ghidorah would just stood there like an idiot and let Kumonga wrap him up in webs. Ghidorah's going to fight back, and Kumonga will be lucky if he gets even a very thin layer of web on Ghidorah.
Also, you're given Kumonga way too much credit in this, like he'll have Ghidorah all wrapped up in a minute. Kumonga's webs are not that fast!
Rodan will act as a distraction while Kumunga sprays its webbing.
...Rodan may be able to stale Ghidorah for a little bit, but not so much to the point where Ghidorah is going to just forget about all the webs being fired at him, just to attack Rodan. Once the webbing starts to hit, Ghidorah's going to forget all about Rodan and destroy the source of the webbing.
If it comes down to it Kumunga will go in for melee. It is also very possible for the giant spider to play dead and surprise the space demon.
...If Kumonga goes for melee, it's going to be destroyed before it even has a chance to get close to Ghidorah.