Sort of. AOL Broadband is actually a brand operated by Talk Talk. They acquired AOL UK excluding the content business back in 2006.
You're right that probably does account for a lot of AOL addresses, though. But the size of Talk Talk as a whole (don't know the breakdown between the Talk Talk brand and AOL brand for their ADSL) is too small to account for even a majority of the AOL addresses, and there are disproportionally many AOL addresses vs. market share compared to other operators like BT.
