That is an observation also made by Lou Dobbs who has said that he has never seen anything resembling salacious or lovey dovey among all their emails.
There was testimony by Strzok that he had an opportunity to review text messages before turning them over to the DOJ IG and his removal of those (sexually) personal messages was approved by the IG. Whether the IG actually had a chance to see them before removal or just took Strzok's word is unclear.