Is he working in the UK? If he's not working in the UK, then ignore everything I have said - different countries all have different rules on redundancy, even within the EU (I know - my team is spread across about 6 countries), and you need to find out how it's governed in that jurisdiction. For all I know, it may be entirely legal in some countries. If you're somewhere like the USA, they seem to be able to let people go for almost no reason, compared with most of the EU, from what I've seen.
If he is working in the UK, is there a chance someone in HR has forgotten he went permie some years ago, and they're doing a round of no contractor renewals?
If he's working in the UK and has been with the same employer, it should count as continuous employment, even with changed names. If the company was taken over by another, he'd have been covered by TUPE for a year anyway. ACAS and similar sites can explain more about TUPE.
If he's working in the UK and someone will replace him in the same role, it is not redundancy, not legally. Some employers would get round it by restructuring so the job role itself wouldn't exist, and the tasks get split out between other roles.
If he's working in the UK and he's been there more than 2 years, he can't be dismissed without a reason - if it's not redundancy, is there any chance it could be disciplinary? There would be other processes to follow there.
You need to find out more facts about the reasons they're giving for letting him go, so you can work out whether it's okay or not within the country he's working in, and then you can work out what options are open to you. It's possible that local employment rules will mean he has to just suckling it up.