As
@razerblade stated, yes, the request to provide translations for anything not in one of the official languages is standard. Note:
this is standard in almost all Canadian immigration and citizenship application processing. The instruction guide states this in the section covering gathering documents and
repeatedly in other parts of the guide (which are in reference to particular documents, but the repetition makes it clear, if it was not otherwise clear, that IRCC wants a translation for any information not in an official language).
As to "
stamps before [your] eligibility period"
TECHNICALLY the date of the stamp does not matter. The applicant does not have to present passports which expired or were cancelled BEFORE the eligibility period, and which otherwise could not be used during the eligibility period. But if a passport was valid or could have been used at some time during the eligibility period, even if only briefly, the applicant is required to present it.
TECHNICALLY the obligation is to translate any information which is not in one of the official languages in any document presented to IRCC. So if a passport needs to be presented, technically the date on the stamp does not matter. It is the validity date of the document which matters.
PRACTICALLY it appears that IRCC (like CIC before it) is at least somewhat flexible, if not outright liberal, in how it approaches this
SO LONG AS . . . well, so long as IRCC does not have concerns and what is in the passports can be reasonably understood without a translation.
So, generally an applicant should get anything that is not in an official language translated,
BUT many times the interview goes well for applicants who do not; often there is no mention of the stamps at all.
In contrast, more than a few forum participants have reported problems, having to follow-up the interview by obtaining and submitting translations, which sometimes results in a significant delay, and for some apparently a long delay (albeit the longer delays are probably related to additional factors).
The worst case scenario, in almost all cases, is that the applicant is asked to provide the translations and that results in some delay. AN EXCEPTION to this arises in cases where the absence of a translation makes it difficult for the interviewer to meaningfully assess the travel dates, such that it might appear the applicant may have deliberately NOT provided a translation so as to obscure or conceal information (which should be a rather rare situation, and would involve numerous stamps which are very difficult to understand).
Personally, I took the risk. I did not have my stamps translated. I had few stamps overall and only a couple which had some terms in Spanish in the stamp. But the dates were clear. The shape of the stamp was clear (there are several well-recognized conventions followed by most countries, so that officials examining passports can discern what are entry stamps, what are exit stamps, and what are visas, and such, at a glance without having to read the details in the stamps). And I had waited to apply well beyond the minimum threshold and I otherwise had what was (with a particular exception, which was the reason I waited so long to apply) an obviously solid case . . . AND, to be frank, I forgot there was some terms in my stamps not in an official language until just before my interview (when I was looking over my documents preparing for the interview -- I had gotten rather short notice -- and there was no time to get a translation).