I agree with the thesis in general but this point is not resonating strongly with me.
Conferences are expensive.
AWS reinvent for example requires you to spend 2000 dollars on a conference ticket and travel to Las Vegas and pay for expensive hotels etc.
Most of the content from the sessions and talks there is posted online on YouTube ... in recent memory they posted them online within a day (full credit to them).
The added benefit of attending conferences in person is very hard to justify IMO. Yes there is networking and yes there are some hands on workshops etc.
Instead of the justification offered in the blog post ... I would say, sponsoring your employees' visits to conferences shows that you treat them well, care about their personal learning and growth, and inturn motivates them to look for synergies between their interests and work. They might end up learning that technique from a free youtube video anyway, but only the motivated ones care about applying it at work.