done a concert tour in 1981 to follow the success of his last album Double Fantasy. There is no reason to imagine it would have been his last, or last album. There had been enough extra music that Yoko released songs in 1981. As well John and Paul were on more friendly terms at least since 1974 when they actually jammed together and sang Lucille, along with Stevie Wonder and Harry Nilson. There are bootleg recordings of this, and can be found online, but it's nothing to be proud of.. it was during John's so-called "long weekend" of excess.
The photo is a rare shot of Lennon and McCartney "together" at least in the same photo, post-Beatle breakup.. in 1974 during a jam session
In 1980, Lennon was listening to music by Paul McCartney, and he liked what he heard, specifically "Coming Up", the catchy upbeat solo hit by Paul. Lennon has said that, "it's a dam fine number.. I just can't get it out of my head", and some say it was a factor in him getting back to the recording studio.
During the 1970s, despite old wounds from financial and management disagreements during the breakup of the Beatles, Lennon still did not totally discount a Beatle reunion of some type. He told friend Eliot Mintz that "if it happens, it happens because we would want to." So it is very conceivable given a warming of relations between Lennon and McCartney that they and the other Fab two would get back together for a concert, album or both.
Lennon would have been 69 today. The only thing possible is to enjoy the music and message he left. Below is the last Beatle performance, on the Abby Road studio rooftop. They performed five songs, and this clip is "Don't Let Me Down".