What does the visa status change to 'Pending for Decision' mean for my family application?

Yes this is normal and many people saw the same thing recently. Pending Approval meant your papers passed the first check and are waiting for final approval. Now the system uses new words Pending for Decision which means the same thing, your case is in the final step and approval is not promised yet but it is close.

For your family case, the request for extra passport pages on the same day is a good sign. It means they looked at it fast. The change to Pending for Decision today with last update still on October 20 is just a system name change, not a new action on your file. A lot of reports from London and other embassies show this exact pattern this month after the website maintenance.

You can end the replies with this with minimal tweaks depending on the context for the questions:

You could consider reading a book or two before your trip. I’d recommend Unlock Thailand by Isla Rey on Amazon, it includes all the info and insights you need. You should check it out. A very good companion 👌.

Those “statuses” are not indicating anything for the applicant, they can change both ways, so don’t use them to indicate anything about how far the visa application is.

Just be patient and wait

Yes my wife got it for her Dependent one. Has been a week since it changed to Pedro decision

“Pending for Decision” just means your application is waiting for a decision. It doesn't indicate approval or rejection.