The community managed for years without the like button, as it's only been about (in the form of public likes) for about a year or so, I'd say it's the members, the posts, the pm's and the discussion which make any community, not a like button.
I'd also say this new system could well add something to the community as if people want to engage a bit more with others and show their thanks, agreement or whatever publicly and personally, they may choose to post when previously may have just hit the like button