Let's speak in terms of entering class because it gets convoluted when you talk about graduating class. The class of 2023 the way you mean it, as I interpret it, is entering class of 2019. Class of 2024 would then be entering class of 2020, who will enter in the fall. While the entering class of 2020 would have entered knowing it was pass/fail, there are many people graduating in 2024 - not a small number I think - who would have taken it scored. This includes anyone from prior years who took a research year, pursued another degree (PhD being the longest), or took a leave of absence for any other reason. This is why I think even 2022 or 2023 is too early to be going P/F without large disruptions.