The company, part of Facebook, now plans to bring in the changes on 15 May, it said in a blog post.
The changes were announced earlier this month and when users opened WhatsApp they were asked to agree to the new terms or else lose the ability to use the platform by February.
The company claims that there will be no changes to the privacy afforded to users, just that some changes will make it possible for advertisers to communicate with users.
"But whether you communicate with a business by phone, email, or WhatsApp, it can see what you’re saying and may use that information for its own marketing purposes, which may include advertising on Facebook.
"To make sure you’re informed, we clearly label conversations with businesses that are choosing to use hosting services from Facebook," the post said.
Other changes, all of which are claimed to be minor, are detailed in the same blog.
Signal was so overwhelmed by the flood of new users that it had to find new data centres to handle the load that the new users brought.
In a tweet, the company said on Saturday: "Signal is experiencing technical difficulties. We are working hard to restore service as quickly as possible.
"We have been adding new servers and extra capacity at a record pace every single day this week nonstop, but today exceeded even our most optimistic projections. Millions upon millions of new users are sending a message that privacy matters. We appreciate your patience."
On Sunday, Signal tweeted: "Signal is back! Like an underdog going through a training montage, we’ve learned a lot since yesterday — and we did it together. Thanks to the millions of new Signal users around the world for your patience. Your capacity for understanding inspired us while we expanded capacity."