Comment by lxgr

Not necessarily. Required certifications, SLAs etc. for safety critical systems are vastly different from those only handling passenger entertainment/connectivity. For example, Iridium has been around for almost 30 years now (launched in 1998), but it only became certified for safety of life applications at sea in 2019, and for aviation around 2010.

Many planes still use completely separate systems for non-critical communication (often Ku or Ka band based geostationary satelliets) and for ATC or operational communication (usually L-band based Inmarsat or Iridium) as a result.