Welcome to the forums! :toast:
A LOT of attractions are set to be open by then. All these have a basis in fact. We might not know the opening dates, but here's what we can assume:
- Star Wars: Galaxy's Edge (confirmed to open in late 2019 at Disney's Hollywood Studios)
- Toy Story Land (confirmed to open this June at Disney's Hollywood Studios)
- Mickey's Runaway Railway (confirmed to open in 2019 at Disney's Hollywood Studios)
- Currently unnamed Harry Potter roller coaster (confirmed to open in 2019 at Islands of Adventure)
- Rumored Jurassic Park addition (unconfirmed, but under construction at Islands of Adventure, 2020 is the rumored opening timeline)
- Volcano Bay expansion (confirmed without opening date, rumored to open in 2019)
- Infinity Falls (confirmed to open this year at SeaWorld Orlando)
- Sesame Street Land (confirmed to open in 2019 at SeaWorld Orlando)
- Rumored Busch Gardens Tampa coaster (unconfirmed, but rumored to open in 2019)
- Lego Movie Land (confirmed to open in 2019 at Legoland Florida)
- Ratatouille ride (confirmed to open at EPCOT, rumored to open in 2020)
- Unnamed show (confirmed to open in 2019 at Universal Studios Florida)
A couple of extremely rumored attractions with no construction on them yet, so take these with a grain of salt. They might not be open (or coming at all) when you arrive.
- Ministry of Magic attraction (rumored to open in 2020 at Universal Studios Florida, but it's likely that the attraction has been delayed)
- Unnamed Mary Poppins attraction (rumored to open in 2020 at EPCOT)
Hope this helped!