It doesn’t say you have to do it now now. And if you click the link it says it will be by the end of the year. And there are a whole host of posts on the logistics & desirability of moving gateways.
There was a North American cluster for v2, a little research would have revealed the plans for v3 clusters along with the almost simultaneous existence of the NAM1 cluster. I think this indicates rushing.
We, the community, are emphatically telling people to NOT migrate v2 gateways until nearer the end of v2 as devices on v2 will be left stranded. Again, many forum posts on this. And no one is pushing anyone.
You, me and everyone else on this forum is TTN because TTN is a set of servers provided for free by TTI for us to use. As an adjunct to their commercial work, we get to read the documentation and other outputs. Depending on where you are are at in terms of experience & technique depends on the results you get. None of us has any rights to anything and if we want to improve things then lead by example.
So YOU, by virtue of using TTN, are in fact telling people to not move to v2 to v3 just yet and YOU could be part of the solution that develops the documentation.
That’s yourself you are criticising here.
As for your choices, if GSM fits your needs in terms of power and tolerates a subscription of any sort, fine. LoRaWAN has many moving parts, but deploying known good devices with known good gateways with an integration to an established dashboard provider is pretty prescriptive. If you want to mix things up, be prepared to get your hands dirty.