Can only talk about Paris CDG, Dubai, and Bangkok on this. At all of them, both ways, my husband used a wheelchair. In every case we were kept informed and moved on in a timely fashion. We were even asked if we need to stop to use toilets, go to any of the shops, get a coffee. Dubai there was even a lounge for passengers using assistance, with a coffee shop.
Only snag was finding where to go to get the pusher, (which had been arranged in advance) as it was never all that close to the entrance.