Starting on March 11, the figures of Google Search Console show a boost of the number of URLs under 'Crawl requests: Discovery'. They are now 75% of the crawls (178,000 in a single day), while they used to be just 25% in the last 3 months.
However, if I analyze the performance of any of such URLs, they show results in the last 16 months, with impressions and clicks. So they were actually indexed and not "discovered" by Google.
Any explanation for this? Should I expect something with this boost of URLs under 'Crawl requests: Discovery'?