Considering that the current all stations service from Beverly Hills to Circular Quay takes 36 minutes, I don't see how 35 minutes is not doable.
And I'm sure the passenger loads will not be problematic at all. There's actually not all that many people that change at Beverly Hills to catch the via Sydenham service. If you are travelling into the city and you were starting from the Revesby to Narwee segment, you could either basically have a seat guaranteed by catching the all stops service. Alternatively, you can choose to bother getting off at Beverly Hills and practically be guaranteed not to have a seat on the via Sydenham service. The vast majority of people I see choose the former. Secondly, apart from Narwee, all of Revesby, Riverwood and Padstow have the limited stops services to/from Macarthur which are a lot more convenient to just get on than having to catch a train to Beverly Hills and then changing trains again.
As far as the afternoon route goes, there is really no reason to catch the via Sydenham service at all if you're travelling to Narwee, Riverwood, or Padstow, because you ultimately will have to switch back to the all stops service at Beverly Hills. The all stops service departs a mere 3 minutes beforehand, so you would likely have been able to catch it anyway.
There is also no issue with passenger loads in my opinion. Rather than give an incentive for people to load onto the already packed to standing via Sydenham services, people should make use of the all stops service, which does not quite get as packed. There is excess capacity on those services so Sydney Trains is rightly removing that incentive to catch the via Sydenham service.
I'm sorry to say this because clearly it is unfortunate for those stations that lose services, but the proposed timetable for the Airport and East Hills Line is a lot more streamlined than it used to be, and a large improvement overall.
The reason why Beverly Hills could not be included in the stopping pattern was because its inclusion would make the Kingsgrove - Revesby quadruplification redundant. The only way a train could stop at Beverly Hills is if it doesn't use the outer tracks on the Beverly Hills to Revesby segment. The whole purpose of the revised via Sydenham services are that they travel unimpeded on the outer tracks between Revesby and Turella.
If you notice, an issue under the current timetable is the delicate juggling act managing the fast via Sydenham service and the all stops service to make sure they arrive in the right order. For instance, on the up route, the via Sydenham service arrives at Beverly Hills only two minutes after the all stops service, so a delay for the latter could cause delays for the former. Or take the down route, where the via Sydenham service departs a few minutes after the all stops service. It must travel at a sufficient speed to overtake the all stops service and get enough space in front of it such that it doesn't delay the all stops service when it merges back onto the same tracks at Beverly Hills. Occasionally, the outbound all stops service is held up at Kingsgrove waiting for a delayed outbound via Sydenham service to overtake. By removing Beverly Hills, there will be less of such issues.
As far as the to/from Macarthur services that will continue to use the inner tracks, if you note, they have been sped up. Kingsgrove, which is an even more substantial station than Beverly Hills, is no longer part of the stopping pattern. Riverwood is where the limited stops services now last/first stop at, then to Wolli Creek. The idea here is that the people that live closer to the city than Revesby should catch the all stops service, although provision is made for Riverwood and Padstow, which have high patronage numbers and are further away than most of the other stations on the segment. Correctly so, the limited stops services and express services via Sydenham should be primarily for people that live further than Revesby.
Of course, the limited stops services also stop at all stations through the Airport tunnel but with the need to serve airport commuters and provide a frequent service, that is understandable.
Four trains per hour during most hours of the day is not that bad overall.
Here, are some of the overall improvements when you consider the Airport and East Hills Line as a whole, if the draft is correct:
- Faster travel times for the to/from Macarthur services because of the removal of stops from the stopping pattern
- Eight trains per hour to/from the Airport (which would really benefit airport commuters) during most hours, even off peak
- An increase from the current two services per hour offpeak to Holsworthy - Macarthur via Airport to three. The third service also happens to be a very fast service, stopping Holsworthy, then Wolli Creek, likely using the external tracks between Wolli Creek and Revesby.