My understanding is the Bundesmarine has 8 P-3s and the Aeronavale 18 modernised ATL-2s (the 2012 upgrade was aimed at allowing an intended OSD c.2032). (Don't know where l'Aero's Falcons fit in to all this.) If the UK and Italy are any guide the replacements will be in much smaller numbers; so its hard to see anything other than off the shelf with, perhaps, some home grown mission equipment.
In 2017 eight NATO members (including France, Germany, Canada, Poland, Italy, Spain, Turkey and Greece) agreed to cooperate on “multinational maritime multi-mission aircraft capabilities”. Don't know if this initiative is still current. As I mentioned of the other thread Turkey and Italy both have ATR-72 based MPAs, Portugal, Spain and Canada operate CN-295s though only the first as MPAs. I also presume Spain's P-3As and ex RNoAF P3-Ms haven't got a long future.
According to an April 2019 article in Jane's Defence Weekly, Boeing was pushing the P-8 to various groups of NATO countries as a temporary stop gap "until the alliance secures its own maritime capabilities by 2035". Methinks, "until 2035 my ar$3 !"