It's worth noting how the last (contentious) feeder pattern change was implemented, including grandfathering - details are here:
https://dcps.dc.gov/sites/default/files/dc/sites/dcps/publication/attachments/Boundary%20and%20Feeder%20Pattern%20Changes%20FAQ.pdf
This was announced in March 2015 and took effect in SY15-16. It allowed for students to continue to their previous feeder for 15-16, 16-17, and 17-18 if they were enrolled. So if you were in 3rd, 4th, or 5th grade that year - you were good. And they allowed for siblings of those who wound up in that feeder to continue to attend.
So, worst case - if this change were to be implemented in 2023 boundary review, AND they followed prior precedent, it would be implemented in SY23-24. So that means if you have a kid at Shepherd, your oldest would need to be in 5th grade by the SY25-26 school year...meaning, they'd have to be in PK3 this school year. That's a lot of "ifs," but should at least make current families feel a little bit better.