The common factor in these deals (and much smaller ones) is that the company being bought has *some* value, but that value is overestimated by the "stupid" big company. I.e. they squeeze an extra $50 million when its really worth only $5million.
The difference between these examples and OPs idea of selling awesome legit templates backed by 3 press releases is that his sites have an income of $0 and a similar value, so convincing a big company that they are a threat will take some accounting fraud and/or an M&A team that is actually mentally retarded or made up entirely of 8 year olds.
You're absolutely right. There needs to be some semblance of value... a fledgling product/service, partially developed and differentiated IP, a high-talent team that can be locked up in employment agreements, and ideally some revenue and a demonstrable business model.
Selling early stage companies happens all the time. My team has bought a few- some ended well, some not so much.
What the OP is suggesting is just silly, however. You can't repeatedly sell shell companies with nothing more than a basic website and some press releases, completely agree. Maybe a handful of times -- but the suckers run out, and your reputation, which is critical in the deal world, goes in the toilet.
But people are also overstating it the other direction as well. Of course strategic buyers do due diligence and seasoned M&A professionals will be painfully aware when they are doing deals that don't have demonstrable financial rationale. But big companies are *really* bad at launching new products or businesses outside of their core business, and can be challenged at times in expanding their core (e.g. international expansion, moving into an adjacent space). Most big companies (e.g. Fortune 500) won't hesitate to spend $2M, $5M, $10M, sometimes more on a tiny company to get one of the things I mention above (team, product, IP, etc) or just to add scale quickly. With deals that size, there is no material impact to earnings. Yes, some thrive and some flop, but it's the cost of doing business.
I applaud the entrepreneurs who recognize this and leverage their expertise to quickly build companies tailored for sale. It's a time-honored tradition and there are unending niches to exploit. But as others have said, you have to have real value for sale.
The OP is not that, not now anyway. With such limited detail it's hard to know if his team has some special knowledge in their niche or not. He may not have a sustainable, repeateable idea right now, but his eyes are open and it may help him stumble across something more substantive. It's an idea worth teasing out. People do get rich this way.