Hi Wobble,
I agree with the point you have made, these verses do not describe JWs. They in no way know Jesus as Lord or have Him as their Saviour.
2 Peter 2:20-21 (New International Version)
20 If they have escaped the corruption of the world by knowing our Lord and Savior Jesus Christ and are again entangled in it and overcome, they are worse off at the end than they were at the beginning. 21 It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them.
However, the whole chapter is about false teachers 2 Peter 2
Sure, we are now have several generations of false teachers from the WT but ultimately, their roots can be traced to those who left the gospel and created their own Galatians 1
Acts 20:29-31 (New International Version)
29 I know that after I leave, savage wolves will come in among you and will not spare the flock. 30 Even from your own number men will arise and distort the truth in order to draw away disciples after them. 31 So be on your guard! Remember that for three years I never stopped warning each of you night and day with tears.
1 John 2:19 (New International Version)
19 They went out from us, but they did not really belong to us. For if they had belonged to us, they would have remained with us; but their going showed that none of them belonged to us.
Blessings, Stephen