Now it is official - the rule will not be applied retroactively.
My citizenship application is being processed. How will the 2017 legislation changes affect my application?
If we received your completed application before October 11, 2017, then only some of the changes will apply to you.
Language and knowledge requirements
If you were a minor (an applicant between 14 and 17 years of age at the time you applied) you won’t need to meet language requirements or take a knowledge test.
If you were between 18 and 54 years old when you applied, you will still need to meet the language requirement and pass a knowledge test.
If you were between 55 and 64 years old when you applied, you won’t need to meet language requirements or take a knowledge test.
If you have received a notice to appear for a knowledge test or language assessment, IRCC will be contacting you about the next steps in your application.
Time spent in Canada
The changes to the amount of time you must be physically present in Canada do not apply to you. You must meet the physical presence requirements that were in place at the time you submitted your application.
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=1077&top=5