Yes, but that's not ruling out changes to each separate program during the year. In fact, at the same they announced that they;re going to remain separate throughout 2018, they announced changes like eliminating rollover nights at Marriott. So more changes within each program are not ruled out during 2018, only the merging of the two (or three*) programs is ruled out in 2018.

* They hinted that not only will Marriott Rewards and SPG merge eventually, but that the separate Ritz program will merge into that too. Thus the confusion over whether it's two or three programs that are merging come 2019.