A common point that Igor makes in discussions about the platform is that it is crypto agnostic. And it's true that it currently supports a number of different tokens. More importantly, it does not have its own token and so there is less conflict of interest. All of these points are great.
However, publish0x only supports a handful of tokens, and only supports Ethereum tokens, with no plans on supporting any other options. While one can understand that it is difficult to integrate new blockchain technologies into the platform, given that there is essentially no long term plan to implement any other blockchain technology, or even desire to do so, it is hard to call the platform crypto agnostic.
ERC-20 Agnosticism (Maybe)
The platform relies exclusively on the Ethereum blockchain and provides indirect support for Ethereum, by adding a very important use-case to ERC-20 tokens. And so while it might be reasonable to call the platform Ethereum agnostic, it is most certainly not crypto agnostic. I do hope that things will change in the future.
Tron integration should be easy, as Tron is in many ways quite similar to Ethereum. Many of the top dapps on DappRadar are Tron dapps. Many others are EOS dapps. So EOS is probably another good choice. But I don't know how much harder it would be to integrate EOS support into the platform. EOS is quite different from both Tron and Ethereum.
Part of the push has to come from the community itself though. We need more quality articles, relating to the blockchains that we want to see integrated on the platform. We need quality articles for Tron, EOS, et al. The more interest that the team sees, the easier it will be to convince them to take the time and resources to integrate the technology.
Either way, until there are at least some long term goals to integrate more blockchain technologies into the platform, it is unreasonable to call the platform crypto agnostic. And none of this discussion implies that I don't like publish0x. I use publish0x, and I think it has a lot of potential as a social blogging platform.