The first “article” listed under Session 1 is just a single paragraph introduction to the topic presented by keynote speaker Andreas Rossberg. Since it seems that the MPLR conference presentations were not recorded, you can watch a related presentation of Andreas Rossberg’s on WASM (presentation starts at 4:47:19) at ACM’s 28th SIGPLAN International Conference on Functional Programming which was held this year in Seattle, WA, USA in September.

Also in case you missed, these are the most recent proceedings for (AFAIK) all of the major PL conferences:

• ICFP 2023: https://dl.acm.org/toc/pacmpl/2023/7/ICFP
• PLDI 2023: https://dl.acm.org/toc/pacmpl/2023/7/PLDI
• POPL 2023: https://dl.acm.org/toc/pacmpl/2023/7/POPL
• OOPSLA 2022: https://dl.acm.org/toc/pacmpl/2022/6/OOPSLA1
• ECOOP 2022: https://drops.dagstuhl.de/opus/portals/lipics/index.php?semnr=16234

And they have ones for prior years