Long-term residency is not enough to secure free movement rights
If refugees end up staying in Europe permanently they can acquire long-term resident status – subject to meeting certain conditions – as per the 2003 EU Directive on the status of non-EU nationals who are long-term residents. This gives them the same rights as that of EU member state’s nationals in certain areas, although it does not bestow an absolute right to free movement on par with EU nationals.
In any event, the UK, along with Ireland and Denmark, are exempt from this directive. This means that the UK does not have to allow non-EU nationals who are long-term residents of other member state into the UK if it does not want to. If it does allow them entry to the UK it is on the same basis as other non-EU nationals, i.e. meeting any relevant skills and income criteria. Therefore, the UK already has additional controls over immigration policy compared to other EU member states.