I agree that a literal 1:1,000,000 chance (right now) is insignificant (who wouldn't, really). However, if the news outlets would have run with deaths and ill effects while the FDA and CDC sit idly by and do "nothing," it would have been orders of magnitude worse for hesitancy issues. The fodder, ill-conceived or not, would have been there for the tinfoil hat crowd.
We have such a short attention span, collectively, that a couple weeks' pause isn't going to do much long term. I'm glad these steps were taken. It allows the message to really get out there that our safety really is at the forefront, before profits and self-aggrandizing behavior. Warranted or not, a change in recommended age groups, gender, or both, for receipt of the JnJ vaccine is the likely outcome here.
Our hesitancy fears may be a little unfounded, as well. After a bumpy start and pauses galore with AZ, the EU is finally getting on track with their vaccination program, illustrating that the public may soon forget if the cases and deaths from COVID continue at their currently high clip.