In essence, businesses don't have moral authority. They do by their own efforts of course, but as long as they are following the law, that's their basic obligation. Most businesses get by with minimum "social contribution"
Now, I can't imagine any business will make a decision like this without considering the consequences for the bottom line. So, they are deciding either the laws are going to change and they are getting ahead of the law, or, that the Goodwill they "earn" with the anti-gun crowd will make a difference to their long term revenue. If this is purely a moral decision, it won't mean anything if the business folds.
I can tell you this, unlike other social gestures, such as businesses giving bonuses to their employees, and the like after the tax cut, if the NRA starts to feel the heat, they will be sending out letters and details to members "do not shop here, or there", "spend the extra $5 and go to this Place A rather than Place B" then indeed, this could really hurt these companies.
Sorry, but I don't believe some High School kids are going to be committed to their cause over a 10 year period. They might like the attention the alt-left media are giving them, going on shows like Ellen and talking a great game, but they will go on with their lives, apply to college, pursue their dreams. Some will even join the NRA.
For many in the NRA, this is a lifetime commitment. It was a case of them going about their business, now they will feel threatened, and this means businesses who turn their back on them will get hit.
If they do, as the NFL learned; there can be consequences. It's any businesses right to make a decision, and I applaud those doing it for reasons they believe in, but they had better make sure their Boards and shareholders are in line with this, or it could be a short term for the CEO.
NOTE: I can tell you why this decision happened so quickly, I looked it up and Edward Stack is Chairman AND CEO. So, this is totally on his head now, if they fail. It might work out for him, if not...