I'm not sure why he says that the A35 will be the entry level AMG with the most true/flagship AMG DNA in it. You can see throughout the video he's trying to put that point across with the grill being the same as other AMG cars, the side skirts are like the C63, having a twin scroll turbo like the E63, exhausts look at the AMG GTS etc. At the end of the day, it won't be on the same level as any of those cars and I have no clue why he implies this could be a replacement to the A45. Having the same gearbox and 4Matic system as the A45 isn't a good thing as they're 2 things A45 owners complain about. I'm also pretty sure the PFL A45 wasn't one of the most exciting AMG cars you could ever own. I found it funny that one of the alloy choices is pretty much the S3 ones.
The things I like I mentioned before, they kept their MMI wheel like interface in addition to the touchscreen, electric seats are standard, proper bucket seats (although Shmee said they're firm and not comfortable if its the same as the C63), the new steering wheel drive mode selector, some of the new graphics on the virtual cockpit like screen (I'm sure there could be some nice themes), AR navigation sounds nice,
One interesting thing though, was about the new A45 potentially having 4Matic+ system. The only hatchback with something like that is the Focus RS so it's good that it's moving to other cars too. I don't think it'll have well over 400 bhp though. It could be that the normal A45 has 400bhp with normal 4Matic but the A45S has 420 bhp and 4Matic +
Overall I don't think you can trust someone called Mr.AMG to review an AMG car without bias but it can be useful to see one side of the story.