## RAW, the familiar retains invisibility when delivering a touch spell. 

Absent further clarification, the only reasonable conclusion is that the caster, and not the familiar, makes an attack roll, does damage, or casts a spell in the situation where a familiar ["delivers the touch"][1]. 

The removal of the pertinent clause from the citations in the original questions implies that this was an intentional change from previous versions of the spell.


  [1]: https://www.dndbeyond.com/spells/2618877-find-familiar