For whole week I have this phone i was trying to register with it into Insider program.
And today it finally registred and even downloaded some fastring configuration.
Seems like MS is really trying hard to add L950/XL into insider program.
From what I have seen Gabe Aul tweet. The 950/XL are not yet part of the Insider programme as there is no recovery.
The WDRT is being worked on to rectify this.