Guardians is definitely in the Whedon mould. The style of the humour and the approach it takes to storytelling feel very influenced by Whedon’s work.
It makes sense. Guardians was made in the shadow of Whedon having just written and directed the biggest superhero movie of all time, and was made during the period where Whedon was in the creative driving seat for all of Marvel’s output at that time, overseeing all their movies (and tweaking scripts as part of that). Whedon’s was a winning formula that they would have been foolish to not stick with.
It will be interesting to see whether the sequel still feels like it carries that heavy Whedon influence, given the change in circumstances.