Depending on further deliveries of the A321 neos from Airbus there may not be a need to source additional aircraft from elsewhere.Probably from STN as will help with crewing. Really don't think LBA will be affected by this re W patterns
Also thinking about this, whilst the news has only recently broken, they must have been in discussion for some time which gives more scope for sourcing aircraft. Jet2 do usually, and I say usually, know what they are doing.