In the case of the 09.54 from Malvern, there is now an 08.56 departure there as well, that will pick up the path of the current 09.50 from Moreton-in-Marsh. This change may well affect travel habits from the Malvern and Worcester area by removing the current yawning gap in departures to Oxford and London between the 08.25 from Foregate Street and the 09.54 - so should probably ease some of the pressure on the latter service.
Indeed there is, that 08:56 is also a 5-car as is (I think) the previous train, 08:13 from Worcester Shrub Hill to Paddington. It's difficult to know for sure how loadings over all three trains will compare with current trains that run at different times (and an additional one in the case of stations west of Moreton) - they might all balance themselves out and spread the load a little, though I suspect as a best case scenario you'll do well to bag a seat if you join after Oxford on any of them. Standing the 15 minutes from Slough to Paddington isn't the end of the world of course, but if it becomes a case of routine standing from Oxford then that's not so great.