Apple will announce its next-generation iPad Pro tablets in April, not March, according to Mark Gurman. Jon Prosser has backtracked on his claim 'from a reliable source' that Apple would host a hardware event on March 23, too.
https://www.notebookcheck.net/Apple-tipped-to-announce-new-iPad-Pro-models-with-Thunderbolt-and-a-mini-LED-display-option-in-April-no-March-hardware-event-this-year.528186.0.html