Your Trustee has 3 years from the start of your Bankruptcy to commence the process to realise his interest in your property. This would normally be by applying for an order for possession and sale of your property. If he is unable to do that for any reason (there isn't enough equity to make it worthwhile) he can apply to the Court for a section 313 charge to be registered. This charge will be for a specific amount (£'000's) and it will increase by statutory interest of 8% until you either sell the property or buy off the charge. It seems like he commenced the proceedure before 3 years and will therefore be able to register his charge.
I wouldn't bother attending the meeting unless you want your Trustee to explain all this to you which you can ask him to do at anytime anyway.