Any individual pictures showing in the blog will not be affected by the retirement. All pictures I've uploaded over the years to Picasa Web Albums are now visible using Google Photos, and Google assures us that the link that make those pictures show up in blog posts will continue to work just fine. But, the full page of ALL public web albums is a feature that they have decided not to continue in Google Photos. They may change their minds - things are always changing at Google - but for now there is no Google Photos link to all public albums. You can get a link to an individual album though, so I have created a page for this blog where I will post those.
To make it look pretty, I take a screen capture (using the Snipping Tool in Windows) of the Album cover. I post that graphic on the blog page, then link it to the Google Photos album. I will do this each month, adding the current month's album to the top of the page.
Check it out, click the "Our Photo Albums" tab at the top of this page. You should see a February album that you can click to see the whole album, a January album, and then a link to all albums before 2016 - using the PWA link to all public albums. I'm trying to get information from Google as to whether that will continue to work.