I'm not sure off the top of my head of all th reasons we might not create capacity facts for a given qtree.
It might be interesting to get a look at how many capacity facts you have for each of your qtrees.
select sd.name storage, qd.name qtree, qd.tk qtreeTk, count(distinct(qcf.tk)) capacityFactCount from dwh_capacity.qtree_capacity_fact qcf right join dwh_capacity.qtree_dimension qd on qd.latest=1 and qd.tk=qcf.qtreeTk right join dwh_capacity.storage_dimension sd on sd.identifier=qd.storageIdentifier and sd.latest=1 group by qd.tk order by capacityFactCount desc;
I'm not sure whether it is important to you to continue investigating this situation.
If you do want to look into it further, it may be interesting to see what changed about the qtrees in question on Thursday, from OCI's point of view.
select * from dwh_capacity.qtree_dimension where tk in (15259, 15260, 11266, 11267) order by name, tk;
It would also be interesting, for a qtree where you can reproduce this problem, to compare what you see in OCI with the output of a listing of qtree sizes from the ONTAP command line, such as "quota report".