None of the PHX flights can be transferred to other beyond-perimeter destinations as the slots are specific to PHX. Ditto for the sole DCA-LAS flight.
If Congress adds extra beyond-perimeter slot exemptions, WN seeking a beyond-perimeter slot exemption for DCA-LAS nonstop service is a possibility with
(a) the PDEW of DCA-LAS being 257 passengers per day in 2019, which exceeds the amount of O&D that AA was carrying on DCA-LAS nonstop flights in 2019 (not solely due to the PDEW exceeding the number of seats available on AA DCA-LAS nonstop flights as AA had some connecting traffic onto its DCA-LAS nonstop flights from other East Coast destinations with the AA hub at DCA),
(b) the huge presence that WN has in the DC market (at least prior to the COVID-19 pandemic) due to its BWI hub,
(c) the connecting opportunities that would be there at LAS on WN,
(d) the significant FF base that already WN has in DC, Vegas, and California to support DCA-LAS nonstop service on WN in addition to AA if WN adds LAS-DCA nonstop service, and
(e) DCA-LAS currently lacking nonstop competition out of DCA due to the DCA perimeter rule (even though AA DCA-LAS is in nonstop competition with UA IAD-LAS nonstop service and WN/NK BWI-LAS nonstop service).
WN seeking a beyond-perimeter slot exemption for DCA-PHX is a possibility if Congress adds extra beyond-perimeter slot exemptions with AA currently being the only airline that serves DCA nonstop from PHX along with the WN hub on the PHX end and the significant WN presence in both PHX and WAS markets.
I probably would expect WN to seek a beyond-perimeter slot exemption for DCA-DEN if extra beyond-perimeter slot exemptions are added with DCA being one of the top remaining destinations that WN doesn't currently serve nonstop from DCA, even though I am unsure if a WN request for DCA-DEN beyond-perimeter slot exemption would get granted with DCA-DEN already having 4x daily nonstops (3x on F9 and 1x on UA).
While there was support for a DCA-SAT beyond-perimeter slot exemption, I am unsure if WN would seek to obtain a DCA-SAT beyond-perimeter slot exemption if Congress adds extra beyond-perimeter slot exemptions due to WN more likely to seek beyond-perimeter slot exemptions for beyond-perimeter hubs such as DEN, LAS, and PHX.
I would probably expect DL to seek a beyond-perimeter slot exemption for DCA-SEA if Congress adds extra beyond-perimeter slot exemptions due to DL having a hub at SEA and DL's desire to compete against AS in the SEA market.