As you know, Google has cut down the snippet length in the search results significantly from when they increased them in December. But this should have zero impact on your rich snippets and rich cards, Danny Sullivan of Google said.
Danny posted a response on Twitter when Aleyda Solis asked how this impacts rich snippets. Danny responded "we haven't made any change to rich snippet, as far as I know."
We haven't made any change to rich snippet, as far as I know
— Danny Sullivan (@dannysullivan) May 16, 2018
I checked a bunch of search results where rich results show and it doesn't seem to be impacting the length or the display of those rich results:
Of course, the normal text snippets are shorter now, but that is for another debate.
Forum discussion at Twitter.