It could also be some potential evidence is discussed verbally between LE / their legal support / while getting ready to alert the judge who it's being put in front of for a decision on approval, to make sure they have all their t's crossed and i's dotted, before it's all put down in court documents, e.g., a search warrant.
So it's airtight and will meet probable cause to justify it -- called a Probable Cause Affidavit [PCA] in some court systems -- and sometimes required for warrants of both kinds (search and arrest), it depends on the laws and jurisdictions.
I don't know if this is the case in NS, maybe it's more straightforward in this situation, "two missing siblings" investigation, with urgency prioritized.
Perhaps some of the potential evidence that could go into a search warrant is discussed verbally with the judge as a "warm up", e.g., something along the lines of:
"While drafting the X of X search warrants for X, we think we have X pieces of evidence or knowledge of likely places to search that are solid and justify the warrant, but Y and Z may not be solid yet or may be seen to implicate certain individuals who are protected as potential victims or witnesses, and we just don't know yet where Y and Z might lead."
So after an overview is discussed verbally they then agree to decide what they're going to include or leave out or redact or un-redact after they have more info.
Again, it varies by locale, but the strategy and discussions behind what ends up going in to court documents such as a search warrant can originate from verbal discussions with a judge before or while they are being presented for approval, even by phone in the middle of the night.
So there could be some knowledge or potential evidence LE has not put in writing in court documents which is germane to their investigation that a judge could be aware of.
And that could change and it gets put into writing down the road once it's vetted or eliminated as things evovle with the investigation.
IANAL and don't know how it goes in Canada.
Maybe someone who is an attorney can correct me if I'm wrong...
Just pointing out a potential aspect of what LE puts in writing in court documents such as a search warrant could have a "verbal history with the court" that is a "read between the lines" subtlety.
LE has to tell the truth but they don't have to tell the whole truth/all they know or suspect IN WRITING in court documents, to protect the integrity of their investigation.
JMO