After seeing how poorly the US government handled the Covid response I hope I don't have to experience a major solar event such as the one described in the article.
Civilian FBW systems (essentially all of which are digital at this point, analog would likely be more vulnerable) are multiply-redundant which provides reasonable protection against upset events. The primary threat from solar events is the induced currents, not direct radiation that is a bigger threat to transistorized digital electronics. Flying aircraft are obviously electrically isolated from the electrical grid (which is where the real damage would take place), and relatively small (compared to hundreds of km of power lines), which would limit the range of induced currents in the airframe.
The real risk to aviation would be a loss of air traffic control which would risk mid-air collisions in busy areas.
There's more info on aviation affects here https://www.skybrary.aero/index.php/Impact_of_Space_Weather_...
Instruments are fine, what could suffer problems are RF receivers (radio, radar, GNSS) but outside of interference during the event and the potential need to reboot problematic equipment, the critical instruments (pitot-static, accelerometers and gyros) aren't particularly exposed. In terms of effects to the aircraft systems directly, all that article mentions are upset events, and those are already a design consideration.
The 737-Max story came about specifically because it was not a FBW aircraft and not designed as such with sufficiently redundant systems. The safety case was that crews could disable the system if it misbehaved, rather than it being essential for flight like a real FBW system would be.
The political reasons are that no one wants a plane full of people talking on their phones and further distracted from listening to the safety briefing and flight crew instructions. Airlines don't want it and passengers don't want it. People do want network access on planes, which is widely available albeit slow. The only sincere technical concerns involve legacy radio equipment (ILS and glideslope), but I'm not aware of any demonstrated interference issues. Plenty of cases of interference from someone parking a large truck or 747 in front of the ILS antenna, though.
How many redundant processors do you need per one "effective" processor you can count on for a typical SpaceX launch?
The most difficult part, historically, is ensuring no single point of failure in a redundant system. Put three computers on a single bus, and it's likely each of the three bus transceivers could cause a complete system failure (so you've tripled the failure rate). In some systems like aircraft FBW, each of the controllers has its own connection to the actuators and its own actuator. The computers are connected to each other to detect if each other have failed, but as a fallback the control surface and actuators are designed so that two good actuators can physically overpower a bad actuator, and this ensures that the mechanical coupling doesn't become the failure point.