Not exactly, most of the projects update their Twitter or any other social media accounts just for name sake. Not even 25% of the roadmap would be completed still they boost about themselves be giving useless updates.
Most projects out there never deliver anything except their useless tokens and if you are lucky a place to trade them but when it comes to reaching their goals the developers fail miserably sometimes because they never had the intention of creating anything and are just buying time until they can exit scam, but in other cases they do not deliver because they are incapable of doing it since they overestimated their capabilities and underestimated the difficulty of the project.