No, the Gulpfile-chain has to be run on demand - and you’d need a host with NodeJS installed to run it in on a server. It is a crude solution to a problem that Grav, really PHP, is not particularly good at handling: Manipulating many large images and handling resources well.
Most of PHPs image-manipulation libraries, both integrated and auxiliary, handle such processes rather poorly as PHP is a high-level language but not aimed at filesystem-manipulation like Python, C, or Node. Thus they tend to fail at emptying memory caches and releasing processes when handling large files (no sane PHP developer will tell you to use it for large file handling) - even images which are relatively small in raw format.
So its use-case is limited to a workflow where an editor, not a writer, finalizes content before deploying it to a live or staging environment. I am looking into apt ways of doing this in PHP rather than Node, but shared hosting just isn’t set up to handle these scenarios with raw images - which writers tend to use (or at least are requested to use for these purposes).