I guess it depends on whether you think having the certification now will help you in the job market as a majority of the job reqs today require MapReduce experience and skills. The quote emphasizes "in the long term" which is pretty open-ended and is an expectation, not a statement of fact.
So it just depends what and when you think having the certification will help your career best. The technology will always be changing...
If you don't need the certificaton now, waiting certainly doesn't hurt; neither does qualifying on MR now, staying up to date, and qualifying on Spark, or Impala, or whatever. It depends on what you need out of it.