You are welcome ...
When you see this message (with the number version : all new catalog will have updated number), just hit OK, then in the "Windows Updates" tab, just select all updates in "Important" field.
There are less updates because MS is providing cumulative updates each time. So, in fact in Windows 8.1, you had to download many updates, and in Windows they are regrouped in 1 cumulative update. Much more easier !
If a new catalog update is available, I always inform in the website "Latest News" page ... then you just reopen the WinReducer Downloader Tool, and the update is visible in "Important" field. Once you will hit "Download" button, the deprecated update (previous cumulative update) will be automatically deleted, and replaced by the new one you download.
In the "Windows Updates" tab, you have also "Various" tools to download, but take care they are executable, so they are not integrated with all Windows Updates, if you want to install them just use the WinReducer OOBE tool to launch them during the 1st logon after your installation ...
Have a good day !