On the whole, the Canes finished up that campaign in the 2nd round of the postseason with a 4 games to 3 series loss to the Rangers.

If you look at his numbers, they definitely weren't bad. 10G/41A/51P in 64 games. 13 points shy of a point per game for the Canes, after being bought out by the Rangers just 5 days before he signed with the Canes. But then that summer the Canes sent him packin' to Philly for a 2024 2nd, 2023 3rd, & 2022 4th.

So, while researching this, it seems that I wasn't going crazy, and there in fact was a trade in place for the Flyers to send him back to the Canes in this year's free agency. The trade was DeAngelo for a prospect - with Philly retaining 50% of his salary. However, the NHL held up the trade due to CBA clause 50.5, which states:

under no circumstances may a Club reacquire, as part of a Retained Salary Transaction, the contract of a player who was on that Club's Reserve List within the past calendar year.

Source

As the article states, if the Flyers didn't retain any part of his salary, the trade would have gone through.