This is unhelpful scaremongering I feel.
If by some reason you haven't had the report the day before the ICPC, ask the chair if it can be stood down and rearranged to a day when you've had time to read the information.
The ICPC itself is very formal, it depends on the practice model your Local Authority use.
There will be representatives from health, education, Police, and the Social Worker. There could be representatives from different agencies such as Probation or mental health services, depending on the needs of your family. There will be a chair called an Independent Reviewing Officer (IRO). Their job is to oversee the meeting and any subsequent plans to avoid drift and delay. They will chair the initial meeting, then a review at 3 months, then 6 months. At these reviews it's decided whether the plans continue, end, or whether the risk is escalating/static, so whether legal advice needs to be sought.
At the ICPC the Police will provide a verbal report. It could be that some of this is confidential so you could be asked to leave the room for a short time. School and health will also provide reports. They'll talk about attendance, how the children present, and whether their needs are being met in that particular area.
The only decision that will be made at ICPC is whether or not your children are at risk of significant harm and therefore whether threshold is met for Child Protection plans. There could be a recommendation to seek legal advice after the meeting, but this entirely depends on how difficult things are in your family right now and if there is a risk of imminent harm to the children.
At the end of the meeting after reports have been shared, all of the professionals will vote yes or no, and they have to give the category for the plan (these are physical harm, emotional harm, sexual harm or neglect). The professionals will also have to explain their reasons. This can be difficult to hear and so maybe think about taking a pad and paper to help you remember the things that are said, as they are going to be important. These are the things that need to be solved to get Social care out of your lives.
If threshold is met and the children are to go onto CP plans, an initial plan will be drawn up with essential immediate actions, and then a meeting will be held within 10 working days with Social Worker, school, health, parents, to draw up a full plan. Then meetings will be held every 4 weeks to review progress of the plan and see how everyone is doing. The children will be seen by their Social Worker at least every 3 weeks, this will include seeing their bedrooms and speaking to them alone. Depending on the worries about your care, the SW might also look in your fridge or cupboards, ask you about your medication or substance use, or talk to you about your relationship.
I would suggest that if you've been the non resident parent and haven't stepped in to assume care of the children at previous points of concern, this could be the worry about your care. Otherwise there could be something in your history, your relationship, or an issue around your mental health or substance use etc. I don't know you so I don't know, but you do need to be honest with yourself as to whether there could be any barriers you need to overcome. If your relationship with your ex was abusive, your children's SW might be worried you are going to struggle to stand up to him to safeguard the children.
Overall, it's quite formal but the chair will be nice and professionals are generally as kind as they can be.