To me the 339 sounds problematic, unless leased.
The replacement wave would take place around 2029-2035 and if bought, these planes would be in service until 2050. Latest around 2040 when both Airbus and Boeing may bring an upgrade eg engine for their 787 and 350 product families, Brussels would be stuck into having to new to be sold and to old by technology aircraft.
Furthermore, i think that getting more A320NEOs and all brand new widebodies may be a too heavy investment for a still fragile SN.
Having Austrian as a benchmark, where the widebody fleet is a mix of brand new and used but young aircraft, i do believe that such a creative mix may be the solution for SN as well.
The 7 NTU's Lufthansa acquired and are supposed to be delivered in the coming months could be such as solution in a mix with brand new 789. This may mean that SN is going Allegris as well, but there are ways to do so.
I see the 339 only as pass trough from ITA - they want to grow via A359 and may shift their fleet, all 339 are leased thus having no risk of sunk investment and the nice part is that they have already the Thompson Vantage cabin and with 30 business and 24 premium eco the configuration is close to SN's optimal seating. Mid life leasing exit options for these aircraft may come around 2034 at 12 years or 2038 at 16 years, thus this may be an option for a bridge model.
