Google's John Mueller says:
Sure, feel free to ping us when you have new or updated content!
Many CMS (including WordPress) also have a Sitemap generator either built-in or available as a plugin / extension. Those Sitemap generators will often also ping Google when you have changed or added content, making it easy for us to crawl and index that content as soon as possible once it's up. Google won't be upset if you ping too frequently (but doing so without changes on your site doesn't make sense either), so ping away!
Which makes it sound like generating a sitemap of new content and pinging Google could spur Googlebot into action. However, Google has said they don't usually use lastmod. Google ignores it because most webmasters don't keep it up to date. Google: We Mostly Ignore The LastMod Tag In XML Sitemaps.
I've seen pinging Google work nicely for fresh content. You can ping Googlebot to come fetch the page quickly after publishing it. That prevents scraper sites from copying quickly and getting Google to see it on their site first. I haven't seen much evidence that pinging Google gets Googlebot to come back and index updated content more quickly.