Western Digital and Micron both announced 1 TB microSD cards earlier today. At 1 TB, these will be the largest microSD cards upon release later this year. Additionally, the SD Association announced SD Express, a new protocol that will be part of the upcoming SD 7.1 specification. SD Express promises to bring transfer rates of 985 MB/s to SD cards and microSD cards, although there is no word on when the standard will be released.
https://www.notebookcheck.net/MicroSD-cards-are-getting-faster-and-bigger.410789.0.html