Wait for 5G Support
If Apple launches new iPad Pros in early 2020, there's a good chance they're powered by LTE rather than 5G.
As we push into 2020, we've seen a number of 5G-powered devices go live in markets around the world including here in the United States.
Apple's 2019 iPhone and iPad models don't come with 5G. Instead, it looks like the company will wait until late 2020 to bring support to its customers.
If you want 5G on an iPad, it looks like you'll probably have to wait until the fall.