I think the modern shows and tie-ins are generally agnostic on the UNIT timeframe.
"I used to work for UNIT in the 1970s. Or was it the 80s?"
Seriously though, I think the new series assumes UNIT stories were set in the years they aired, to hell with original intent and continuity concerns. Certainly, Jo Grant's appearance in SJA seems to imply The Green Death did take place in 1973. And in The Snowmen, the London Underground map the Doctor had was taken from 1967, when Web of Fear originally aired.