Nothing official yet that I've seen/heard. Only semi-official thing was via the Community Forum boss bloke a few months back:
I think this was in response to a fairly creative "they're not telling us anything, so we'll just go ahead and make shit up" thread on the forums
Someone did find UK trademark registration applications made by Frontier for some other properties: Coaster Park Tycoon, Safari Park Tycoon and Water Park Tycoon were all registered 2013/2014. Then in 2015 there are records for Planet Coaster and Planet Safari. (
https://euipo.europa.eu/eSearch/#details/owners/230794). Whether these are entirely separate IPs, planned expansions, or just them hedging their bets is unknown, but Planet Safari is the most recently registered one, so whatever they do, expect animals to be involved somewhere.