Winds of change are sweeping across the landscape of MLB rules. A group of rule changes were recently announced. Several of these changes were deferred until 2020 allowing teams time to adjust. However, note this change which is effective immediately:
Trade Deadline: The trade deadline will remain July 31st; however, trade waivers will be eliminated. Players may be placed and claimed on outright waivers after July 31st, but players may not be traded after that date. (from official MLBPA release cited above, italics by this author)
Yes, you read correctly.