This sort of thing still happens.
In summer there is a weekly Thomson charter flight from BRS to Cancun in Mexico using Boeing 767 aircraft that stops at MAN outbound for fuel.
The weekly summer Thomson charter to Sanford, Florida also used to do the same but for the past two summers has managed it non stop though I believe that under certain weather conditions it might need an en route fuel stop but, and I stand to be corrected, I don't think it has been necessary in the past two years.
Presumably the reason is commercial - TOM could operate these flights from the longer Cardiff runway - and looking to the B787 which Boeing says will be able to operate to the likes of Mexico and Dominican Republic from the existing BRS runway without load penalty.
In the past the Thomson MD has said that BRS would be amongst the first group of UK airports to see the B787 once it was settled into TOM service, though the bulk of its work will clearly be at much bigger airports such as Gatwick and Manchester.