I disagree on several points.FWIW, and I realize they are different brands, designs, etc... but some context with another car might be useful to someone:
Early Tesla Model S went through this almost identical concern and speculation. Original MS was produced with 3G only, and of course was highly reliant upon WiFi/Cellular for connection back to the mothership for car updates/etc as well as standard on-the-road Infotainment streaming and services. Later builds were produced with 4G/LTE (I don't know the cutoff point), e.g. my former "Sept 2015 Build" shipped with 4G/LTE as standard. IIRC in the late 2015 timeframe, Tesla came out with a retrofit "4G/LTE Upgrade" for early production models that was effectively a board to replace the 3G modem/built-in SIM. Tesla did not do a recall or provide some sort of free campaign to make the change. It remained a customer responsibility to upgrade or not, and as you'd expect there were owners on the forums that were @%(*#%$'d off having to spend a penny to (optionally) take advantage of the latest cellular standard that newer builds supported by default. IIRC, parts back then were just over $100, labor close to $300 US. While it was just a little board needing to be replaced, the entire MCU (big center screen) had to be removed to get to it in the depths under the dash, then vehicle software and connectivity had to be updated by Tesla Service to match.
My point being, some owners feel entitled for nearly a lifetime, but I don't see any auto mfgr being responsible to maintain future cellular and other connected technologies outside their control, once a vehicle or product with predefined specs is sold. I expect support for the latest standards in new MYs when I buy, so I've future-proofed myself as much as I can -- no different than how I've purchased PC/Mac and other tech for 40+ years. It's then great if a mfgr like Volvo has designed their vehicle or product so I can optionally upgrade or later retrofit at some reasonable price (whatever that may be to me at the time), vs having to purchase a new model -- at least I have a choice. I see those sort of options made available to owners as a potential benefit of the brand when considering my next purchase, even if I don't make use of the upgrade/retrofit myself. I won't likely keep my 2020 long enough to see 4G/LTE phased-out as is beginning to happen to older vehicles with only 3G, but even if I did, I would not expect Volvo to pick up the tab. As has been said, it's great Volvo is working on a solution for 3G-only vehicle owners to consider. We'll see what they come up with.
1. If car manufacturers build their cars to "talk to the mother ship" or with connectivity in mind, future planning is imperative.
2. Future planning should include accessible modules that are plug and play ready and user upgradable. I.E. Think of a computer processor.
3. I'd have no qualms paying a few hundred bucks for the modules at the parts department, if the modules were in the glove box, or some logical area that requires minimal effort to reach. And then everyone purchasing a module could easily pop out the old and insert the new.
Unfortunately, the modules are probably going to be far cheaper than the labor necessary to install them. Poor forward planning on Volvo and other vehicle manufacturers' end.