There seems to be caveats, but as far as I am aware of, are not known. The lifetime kills and current honor rank have asterisks next to them so I am sure there’s some conditions regarding them, but says you will ‘retain your lifetime highest rank’.
So if I take that for face value, I would presume you get back to your highest lifetime rank? Perhaps Kaivax could elaborate.
Either that or it just simply is saying where it is notated of your highest life time rank that it will remain as such. No clue tbh.