I live in France – do I need EES or Etias to visit my son living in Sweden?

I have French residency under the Brexit Withdrawal Agreement. My son lives in Sweden. If I fly to visit him, do I need to register for EES? If I fly from the UK to visit him, do I then need it? And when Etias is introduced will I need to register for this if I visit any country within Schengen other than France? 

Neither EES or Etias is intended to affect non-EU citizens who live in an EU/EEA country with a long-stay visa or residency card as their visa/card gives them the right to enter the Schengen area. 

So, no, as long as you keep your WA residency card with you, there should be no requirement for you to register for EES or to have Etias authorisation for these purposes.