Yes- the list of guaranteed trains during strikes is usually the same. If you can buy the tix for the trains appearing on the current “Guaranteed Trains” list—then I would buy them. Trenitalia normally has to wait until the European train timetables are officially released on June 14 before it will sell tickets on its website.
You may find you can buy them now if you check www.TheTrainline.com. This is a company Trenitalia contracts with to sell its tickets.
The private high-speed train company in Italy running trains everywhere you need is called “Italotreno.” It has its own high-speed “italo” trains that compare well to the Frecciarosa trains of Trenitalia. the national train company of Italy, Italotreno will have its own tickets on sale now for June and beyond at www.Italotreno.com
Italotreno will also be a target of the June 19/20 strike and, like Trenitalia has its own list of “Guaranteed Trsins.” The problem is that Italotreno changes its list and lists guaranteed trains less than a month before a strike happens,
There are 24-hour nationwide train strikes throughout Italy now scheduled to begin on June 5, 12 and 19. Because they all fall on Fridays, the likelihood is very high that they will occur. The June 19/20 strike begins at 9pm on June 19 That means trains will get you to your destination providing the arrival time is by 9pm on June 19.
That said, a couple workarounds are to book an intercity bus to your cities. Two sites to check are Itabus and Flixbus. You also could overnight in Naples and delay your train day to June 21.