Madison and Nick both died, the only original cast members left (currently) are Strand and Alicia... though its been rumoured that Daniel Salazar might show up again next season, he wasn't in (or even mentioned in) the most recent season.
It otherwise has a tonne of new cast members; Morgan (from TWD), Al (Shannon from Lost), John Dory (Gunslinger type feller), a woman called June, and a like 12 year old girl whose name I can't remember. And they were joined by a couple of newbies towards the end of the season; a trucker lady, a guy in a wheelchair, and a guy who makes craft beer.
To be honest they practically rebooted it... It feels like a totally new TWD spin-off that happens to have Morgan, Alicia and Strand in it. It's even set in a totally different place (southern / middle America, rather than being mainly based in California and Mexico). It has a fairly strong Western vibe (even the opening credits / music are different and have that vibe).
I actually really enjoyed the season though... More than the earlier seasons for the mostpart. And more than a lot of TWD. Morgan gets a ln absolute boatload of character development, as does Alicia, which neither really got previously. So it's like a new show but I personally think a pretty good one :joker:.
Though they have brought over the "various ninjas!" concept from TWD with signature weapons etc... Like Morgan is still "stick ninja", John Dory is a cowboy style "revolvers ninja", Alicia is "Assault rifle ninja", Al is... Err... "Massive armoured truck with mounted machine guns ninja".
ALSO re: Madison it is made quite explicit that she's dead and explained how she died. She's in the season via flashbacks but you DON'T see the death and you never see a body. So y'know. Pinch of salt there.