In verses 1-3, 15-20 Jesus was talking about the destruction of Jerusalem in A.D. 70. In verses 21, 22 where He mentioned the Sabbath day, He was referring to the great tribulation which are the Dark Ages of tribulation in A.D. 538-1798 when Christians were persecuted and martyred for their faith by the Church of Rome.
Yes, Jesus expected His followers to still be keeping the seventh day Sabbath then and now. We read in Luke 23:55, 56: And the women who had come with Him from Galilee followed after, and they observed the tomb and how His body was laid. Then they returned and prepared spices and fragrant oils. And they rested on the Sabbath according to the commandment.