DS2 is 5yo, in yr1, and has a dx of ADHD/DCD, hypermobility and still being assessed regarding ASD, sensory problems, speech and language delay. He can often take hyper to a whole new level. 
His school is doing some of the things you are mentioning with varying success. Most of it is helping, but it often takes awhile for the results to show. The thing is, his school is not looking at his dx at all. They go according to his needs. We discuss what difficulties he appears to be having during IEP reviews, and then discuss ways that we (both school and at home) can support/help him in those particular areas. Rarely does the dx even get mentioned, as it's kind of irrelevant IYSWIM.
If the senco is calling a meeting with paed and other people working with your DS, it sounds like she's putting together a multi-agency meeting, which is actually a good thing. Make sure you attend! And if, in the meantime, you are not comfortable with some of the things they are doing, arrange a meeting with the senco and ASK her specifically about those things you are uncomfortable with. She should be able to advise you the reasoning behind their actions, and if there is something you feel may work better, she should help you get it implemented.
It's important to remember though, that your DS's behaviour at school is possibly very different to his behaviour at home. At school, there are all the other children, other distractions, noises, changing schedules, all sorts of stimulating sensory stuff that is so disruptive and distracting. DS2 has a separate area in the classroom, and it's used fairly frequently by DS2 with his TA, as he needs little built in "breaks" during the day to give him time to calm down regularly throughout the day, rather as a preventative measure. It keeps him grounded, if that makes sense.
Sorry, bit of a ramble there, but I wouldn't let yourself get too hung up on the diagnosis. School needs to support his particular needs, regardless of what the diagnosis is. If you think they are not, then speak to them about it, calmly, rationally, and be prepared to offer suggestions as well. But also keep in mind that if they have a good reason behind a particular support that is lined up, sometimes it's good to give it a chance and see if it works. If it doesn't, it just get chalked up to "nope, didn't work" and something else can be tried.