I have just talked to the live English information line at Trenitalia, and the lady there, who was very helpful, told me that they have received no official information about a strike for Trenitalia services for that day.
She said if there are strikes at any time, they are only informed only one week before a strike, and to call back one week before your travel date to find out what is happening.
I imagine this applies to any date where strikes are in the wind.
She said they will not inform customers by the email you logged in with when you booked your tickets, it's up to you to keep checking.
They are still selling all tickets for that day, of course...it's a business.
If your train is affected and cancelled, you will be put on the next available train......if there's room!
If you choose not to travel that day it sounds like you ??may get refunded for non-refundable tickets, but only if there is an official notification of a strike.
So.... it's either wait and see, or leave it till a week before, or cancel now, losing money and rebook for a different day.
I'm amazed I actually got through to talk to a live agent in under 10 minutes.
The link is at the bottom of the trenitalia website, and there's an online chat function with restricted hours.