Have got my 1994 booked in to have the pads replaced next week as I was aware they needed doing.

As I drove out of the petrol station last night my brake light came on.

My question is this,will I be able to re use the indicators or do they have to be replaced

They are quite new replaced with new pads prior to me purchasing the car.

I assume that when people are talking about splicing and joining together it is because of general wear and not just because the wear indicator has activated.

Unless the LS is unusual, the wear indicator is embedded in the pad, so new pads=new wear indicators.
Joining/splicing is usually to cancel the warning light when using pads that don't have the wear indicator connection.

No I understand that the wear indicators are seperate to the pads.

If they are worn through, they will need replacing to give you pad wear warning
in the future.

People are joining the break back together as a temporary measure to turn off the warning lamp, or if the wire is broken elsewhere.

I dont own a LS but suspect the indicators prob just push into the pads so are seperate , you normally get new indicators with the new pads.