nope, but the results returned by this endpoint could also be obtained via the other endpoint:
it wouldn’t be as efficient to get all the data using the latter endpoint if you want to get data to exactly match the iNat phenology charts, but the latter endpoint offers more options to allow you to get the data in other formats – for example, by day, by week, etc.
just for example, here’s how you might get flowering eastern redbuds by month of year:
https://api.inaturalist.org/v1/observations/histogram?term_id=12&term_value_id=13&taxon_id=48502
but if you to see things change by week, you could use: https://api.inaturalist.org/v1/observations/histogram?term_id=12&term_value_id=13&taxon_id=48502&interval=week
(which you could also quickly visualize at https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram.html?term_id=12&term_value_id=13&taxon_id=48502&interval=week)
(just my own observation about the redbud data above: it looks like it’s really heavily influenced by the annual City Nature Challenge. not sure if there’s a good way to remove the effect of that event in this case.)