There's been no push for this month's issue of CoroCoro in regards to S/M news, so I'm not expecting much. We could get some coverage on the final starter evos and what not, but I doubt we'll get any new info.
I could see Decidueye, Incineroar and Primarina getting an article, but like you said probably no new info other than just a wrap-up of previous news.
So a round-up of the new Pokemon, Alola Forms and Ultra Beasts total below, and how many of them we had officially revealed in trailers up to this point. The number of how many were revealed officially is in brackets
New Pokemon: 81 (60)
Alola Forms: 18 (14)*
Ultra Beasts: 8 (3)
*Alolan Dugtrio was not officially revealed in a trailer, but did appear in the demo so I counted it.
Rounding up these numbers looking at the unrevealed stuff the datamine leaked, that leaves 21 new Pokemon, 4 Alola Forms and 5 Ultra Beasts.
Among the 21 new Pokemon whose names we won't know until after release include the evolutions for Pikipek, Crabrawler, Wimpod, Salandit and Morelull, as well as that core thing placed before Solgaleo. And then there's also the anchor, bubble spiders and crown of thorns lines. We kinda worked out who was Marshadow (aka the little black creature with the fiery eyes), but we won't know its true identity for sure until after release. The Alolan Geodude and Diglett line we won't know the type or abilities of until release either.