SCE TOU-D-A and TOU-D-B Forced Migration to TOU-D-Prime Date

[MIT_S60]

Do we know when the forced migration is happening? It seems like they haven't updated the text in a while on SCE's website:
We currently plan to close these grandfathered rate plans and move customers to the lowest-cost TOU rate plan available in late 2020.
SCE Grandfathered Rate Plans