It's not so much the timing as the airport's comment about how it is great for 9am meetings showing how out of touch they are with their passengers and the realities of travelling.
I defy anyone to get to a meeting in central London by 9am.
From an 8.25am arrival it would be a lot more than 2 mins to get to domestic arrivals (it will be more than that to get the doors open, even if the 8.25am is at the stand), then walk to the Heathrow Express, then wait for the train, then get to Paddington, then get to the meeting.....
The vast majority would be going on from Paddington to elsewhere in London as well.