John Mueller from Google said that merging content is always more challenging than a basic site move. Meaning, when you take a look at your content on your site and decide to merge a bunch of the content into fewer URLs, that takes longer for Google to handle than moving a site from domain A to domain B with no other changes.
John wrote on Bluesky, "Merging is always a bit more challenging than a simple site-move,." He added that "I'd just give it time."
This was in response to Martin SEO McGarry who wrote:
Hey, So I 301'd a page, 2 weeks ago to merge 2 pieces of contentLogged out rankings shows the new merged page has successfully rolled out to all old queries 👍
With me logged in to Gmail, I get personalised results and a featured snippet of the old page still
Different cache systems?
John also responded to the second part saying, "Also, even with a site-move, if you explicitly look for the old URL, it'll show it to you even a long time later ("you seem to know what you want, here it is" -- content from the new one, with the old URL)" John said something similar literally a decade ago - that if you specifically search for old URLs, Google may give them to you.
Google also said that moving your full site at once speeds the migration progress for Google Search.
Google has pretty detailed documentation on site moves and URL changes so check those out.
Forum discussion at Bluesky.
