based on this post on their forum, it doesn’t seem so. Not sure why and I was surprised about this.
Anyway, based on the post, there are other ways to contribute back, including code, translation, testing, and advocacy.
Another way is possibly to donate to 3rd party services that host Nextcloud and offer free accounts (to some extent). I’ve seen some on Open Collective. This may help those services maintain a good number of free accounts for newcomers or those who need them.