According to a source within WWE, CM Punk will indeed be taking some time off from WWE following WrestleMania 29.
The reason why Punk is taking time off has been rumored for several weeks now, with reports claiming he is either injured, frustrated with WWE creative, or is burnt out after a rigorous schedule in 2012/2013.
While one or more of the above reasons could be true, WZ has been told that the creative team currently doesn't have anyone in mind to put Punk against after WrestleMania, so the decision was made to give him some time off so he can rest up.
Punk is still being advertised for the WWE tour in The UK following WrestleMania, however WZ was told those advertisements have been running in The UK for quite sometime now, and are likely outdated. It is possible, like in The Undertaker's case, that Punk could be given time off and still make a special appearance during The UK tour.