i received a call yesterday about a case raised by the IFL for a flight last friday but when called i did not recall (i was too distracted by 3F really kicking off at the IFL and barely recall putting my email into the IFLs device)

anyhow they did not tell me what the case was about initially, but near immediately made the pivot to security verification which was the standard BA process of first line of address, postcode, PNR. so there is some detail missing from the OPs post, it still sounds of a pretty standard call and quite unlikely they would disclose why they are calling unless they knew they were speaking to the person the case relates to.