I don't think new ipad pro will be here soon and here is why

[rui no onna]

Apple launches devices when it's ready.

I'm sure Apple prefers customers buy the high margin iPad Pro, not the cheaper iPad. The refreshed iPad (2017) was ready first so they launched it first.

This pretty much. Given the new iPad is mostly cobbling together existing parts rather than requiring significant development (probably A10X or A11X), it's quite understandable that this device was ready first.

 

[gobikerider]

Looking at a calendar for April we still a multitude of possible days for them to announce a event. It wouldn't surprise me