I've heard similar. But it's not that most don't want reunification. It's more of a concern for the logistics. Northern Ireland economy relies heavily on the public sector, and Ireland might not be able or willing to foot the bill. Which means that without socialism, the choice is framed as colony or collapse. The Irish government might be able to offer an alternative if it came to it. Make a transitional arrangement while private sector jobs are found or more public sector jobs in Ireland to balance things out. Probably not possible while it's part of the EU, which might be tempted to sneak attack Britain but will probably be salivating over doing what it did before. This is very much an armchair position, though!