Well, I'll answer that on pretty easily for you.
Frankie and 343i said that the only reason they were able to include Halo CE in this collection was because of dedicated servers. With they, it was possible to mostly fix the horrendous netcode and lag.
Now, we all know the dedicated servers are nowhere to be seen in this game, which means that it's running of P2P connections, leaving Halo CE to be a terrible, horrible, full of lag experience.
So, that why I never voted for Halo CE on the Team Slayer playlist, and I still won't until/IF 343i introduces the dedicated servers.
H2A is mostly lag with a garbage frame rate on some maps but people love it.... I've had plenty of enjoyable CE matches. More so than H2A