Hi,
Yes I think you are prob sending mixed messages if you give bottle and then end up BFing anyway before bed.
Has your LO ever settled independently for sleep? Eg at nap time? If not, you will need to do some sleep training (eg gradual withdrawal GW) to help.
If you are going down the GW route, IIWM I would prob keep the BT bf for now but make sure you don't feed to sleep so LO learns how to fall asleep on their own, using the GW technique. One way could be to do a BT story after the bf and right before bed, to break the association of the bf being right before bed.
Then, once LO can fall asleep without bf to sleep, then stop BFing at BT and offer bottle/cup instead (if you still want to keep a drink of milk at BT). You could also, if you want, bring the bottle/cup a bit earlier eg before bath.
On the other hand, if your LO can self settle already, and it's 'just' a case of teaching him that he no longer gets a bf at BT then I would switch straight to bottle/cup and stick with it. Don't offer a bf as well/instead or, as you say, this is just sending mixed signals.
I think you could probably focus on just dropping the BT bf for now, if that's what you'd prefer, without necessarily tackling the NFs as well. You might find that once you have taught your LO to SS at BT without a bf that he stops waking for feeds in the night too.