Sending to a new address adds (some, not much) plausible deniability it wasn't just sent to a new owner. Sending to a previously used address ensures that it's visible the original owner is the recipient.

If you're consolidating I would just generate a new address anyway, rather than reuse an old one. There is no downside to generating a new address, the fees will be calculated by the number of inputs, the output is still one either way.