Wyke completed his move to League One rivals Sunderland following a medical on Wednesday afternoon, with the Wearsiders having brought in the ex-Carlisle United and Middlesbrough targetman for a fee in the region of £600,000 following a lengthy pursuit.
The move was only sanctioned after Bradford made successful moves to bring in a ready-made replacement in Irishman Doyle, who has joined City on a two-year deal for an undisclosed fee from North End.
The Dubliner moves to Valley Parade after turning down moves to Peterborough and Aberdeen earlier this summer after failing to agree personal terms.
Doyle joined Preston in September 2015 on a season-long loan from Cardiff City and scored four goals in 15 league starts and 13 appearances from the bench during that 2015-16 campaign.
The 30-year-old joined permanently in the summer of 2016, but found his opportunities restricted and ended the 2016-17 season on loan at Portsmouth.
He spent two loan stints at Oldham last season - interrupted by a spell on the sidelines because of a blood clot - which saw him net 16 times.
Meanwhile, Wyke has become Sunderland’s 11th summer signing after completing his move to the Stadium of Light.
On his move, Wyke, who has signed a three-year deal, said: “I am delighted to get it over the line so that I can concentrate on my football again.
“It is a massive club, and coming from the north east, I know exactly how much it means to people.
“The one thing that everybody wants here is promotion, so we have to get that and win as many games as we can.
“I cannot wait to get started.”