Probably no later than the early 80s. Robin Hood and Song of the South characters started to become much rarer by then.
That picture looks like it's from Disneyland, given the big-pupiled Pluto there also. That Pluto was never used at WDW.
I also find it weird that Pete is not meetable, and yet we can still see images of him in the parks. He appears in Storybook Circus, both as the proprietor of his own Silly Sideshow (for which you have to enter through his big mouth!)...
...and as the circus' resident strongman:
Back when this was known as Toontown Fair, the bathrooms were called Pete's Garage:
At the Studios, meanwhile, Pete also appears in Mickey and Minnie's Runaway Railway, as a construction worker busting up the ground with a jackhammer, who seems to take sadistic delight in the racket his jackhammer seems to make:
Finally, at Disneyland's Toontown, if you look up at the second-floor windows, you will notice that Pete apparently sells prosthetic limbs, harkening back to the days when he had a peg leg (hence the name "P.L. Pete"):
But yeah, I'm not sure why Pete himself is not meetable. I've never even seen a costumed version of him at all, outside of this one Disney ice show about Mickey (Pete was in a scene about "Steamboat Willie").
