I know Peter Linz took over Ernie in mid-2017, but I don't know if we should say that Billy Barkhurst performed Ernie until 2018 considering he performed him in this episode, which aired this year, and who knows if we'll hear him as Ernie some more this season. We probably won't hear Peter as Ernie on the show proper until next season. Is there anybody that agrees or disagrees?
There's been some discrepancy as to what we've considered the end dates for performer tenures, but it's normally the date when a performer officially retires or passes. For example, we note that Kevin Clash performed Elmo until 2012, when his resignation happened, even though his later performances were featured in episodes as late as 2014. When there's an overlap like that, when it's clear that a prior performer is not returning, I see it as less confusing to use a solid date (whether it's on the year or a year prior) to indicate that transition.
Not to mention we don't list end dates for posthumous years. The end dates for Jim Henson's characters are 1990, not 1991 (when MuppetVision 3D came out) or 1993 (when Rowlf: Ol' Brown Ears is Back came out), for example.
Yeah, the page already says Barkhurst did Ernie into season 48. The credits section needs some reformatting though (it's redundant to keep saying Ernie for every episode, when that's the only role we have for him outside of two earlier "additional Muppet performer" gigs). The stage shows could use separation (or clarification) as well. I'll work on those later.