Although Apple has already announced a March 25 event, it seems like the updated tablets will not be there, because the Cupertino-based tech giant has just introduced the new 10.5-inch iPad Air and 7.9-inch iPad Mini. However, there is still no official info regarding the rumored iMac Pro upgrade.
https://www.notebookcheck.net/Apple-might-upgrade-the-iMac-Pro-soon-10-5-inch-iPad-Air-and-refreshed-iPad-mini-revealed-today.414650.0.html