Additional advice, please?

June is in 3 months. The current strikes, which aren't that bad already, should have abated by then.
Strike days are typically announced over a week in advance, and cancellations are known the day before, which gives enough time to book another train.

What you could do right now, as extra insurance, is buying refundable Inoui (not Ouigo) tickets on another train to Bordeaux and another train from Avignon, on the same days. Then, if by end May (7 days or more before your travel dates, check fare conditions), no strikes are on the cards, you can cancel them for free.
And if there is a strike announced, having two tickets on two trains doubles your chances of having your train not cancelled, and if your original trains are not cancelled, you cancel the extra tickets and only lose 19€/ticket.

Brilliant response from Balso.

And I don't know that I would leave it so late to arrive in Paris the evening before a 9:15 pm flight anyway. I would buy the replacement ticket for a time earlier in the day, to give me more wiggle room should something go wrong.

Thank you very much balso! Great idea!

Kim, our flight leaves at 9:15 am the following morning after arriving back into Paris via train the night before. Still pretty close for comfort if there are continued train strikes.

I appreciate the help. Thank you.

Yes, it's way too close for comfort for me. You need to be at the airport at 6:15 in the morning. If you find out Saturday evening that your train is cancelled (or if there is some other disruption that eliminates your train or gets you stuck somewhere along the way ) you don't have any way to get from Avignon to Paris on time, other than finding a rental car and driving through the night. Avignon is near (i.e. doesn't take long, about three hours) from Paris via train, but quite far distance-wise (more than 400 miles / about seven hours of driving).