The well-known tipster Ishan Agarwal has announced on Twitter that he has found out when the new OnePlus devices will be unveiled: May 14. This has not been confirmed by the OEM; however, the date is in line with its launch schedule from last year. According to rumors, this year will see multiple variants of the device in question.
https://www.notebookcheck.net/OnePlus-7-series-to-launch-on-May-14-new-rumor.417275.0.html