Yup, this is in scope for this bug. We now call `formatPhoneNumber` when adding number containers to the conference call list. These phone numbers have a bold font weight, and if we don't set this font weight for our fakeView, the ellipses calculation will be wrong.

https://github.com/mozilla-b2g/gaia/blob/ecb5f5f725d67d8b6d658178ac65885febf26f02/apps/communications/dialer/style/oncall.css#L755