I think BTS is a stronger hold in terms of the EOS "threat" than STEEM. At least we know there are teams looking to implement the EOS into Bitshares. @stan talked about this a number of times including the "bench" team that is actively working on a hybrid chain for institutional investors.
Thus far, we have no idea what the STEEM developers are planning to do with EOS, if anything. It does not mean there are not plans, just we havent heard of anything.