Closing this out because it was fixed quite a while ago. There were some other clipping issues cause by overflow: hidden and that fix also solved this.
Overflow is still hidden, but it was moved and some padding was added, which gives text a little extra space in cases where it naturally overflows a little bit.
https://github.com/discourse/discourse/commit/fa21b398755ccf3c523d0e0262567dbdc510de05