This isn't the same as Microsoft's embrace, extend and extinguish strategy at all. Microsoft's strategy was to add incompatible extensions to existing standards, use their built-in user base to make them de facto standards, and thereby have a technical advantage over competitors. Google did not add incompatible extensions to RSS. There is no standard for syncing RSS readers. They could overtake their competitors because they're Google, but they weren't poisoning the technology itself to do it.
This is just the risk you take in relying on a 3rd party service, particularly one with no obligation to you. By all means, distrust Google, and be cautious of depending on services you don't control. This is good advice that should be spread far and wide. The analogy to Microsoft just muddies the water.