It's no secret that the "Merge tabs and apps option" wasn't exactly the most popular feature of the Android version of Chrome. Google itself pretty much confirmed that when it stopped the practice of making it a default for fresh Chrome installs. However, it seems like its (lack of) popularity was still overrated because the latest, version 51.0.2700.2 of Chrome Dev for Android has completely ditched the option to... well, merge apps and Chrome tabs into one big list in one's multitasking, i.e. recent apps menu. In other words, it does seem likely that one of the next stable releases of Chrome for Android will also get rid of the said option.
So, this probably marks the end of one of the most polarising Android features in recent history. On one hand, hardcore multitaskers loved the ability to mix their apps with their browsing tabs in the recent apps menu, but on the other, casual, i.e. the majority of users felt like the "Merge tabs and apps" option simply creates one big and cluttered mess of the so-called multitasking screen. Regardless of its mixed reception, Google's decision to completely phase it out of Chrome isn't completely surprising as the company has been looking to streamline its products as much as possible for quite some time now.
What all this means is that if you're the type of person that loves mixing his or her Chrome tabs with recently opened apps, you should probably not install the next stable Chrome update once it hits the Play Store. On the other hand, if you're stuck with the said option and can't wait to get rid of it, disabling it is actually a piece of cake. Naturally, this change is still not official and can only be seen in Chrome Dev, but features showcased in it make it to the final app build more often than not. After all, Chrome Dev is primarily used as means for Google to give app developers and users a brief preview of what to expect from its browser in the very near future. A future that is definitely not looking bright for the "Merge tabs and apps" option.