No, this is intentional. Please refer to dmg04's tweet here:
[quote]Looks like all strikes will be available at Grandmaster difficulty next week, so fret not. Ample opportunity to finish gilding over the final weeks of the season.
This week is another opportunity to put some spotlight on the new strike.
See you next week, Gilded Conquerors![/quote]
https://twitter.com/A_dmg04/status/1382017854417948672?s=19