Does The Gospel come filled with Calvinist freight? Yes, of course I agree with C.H. Spurgeon whom said that, "Calvinism is the gospel, and nothing else."
If one fully understands the gospel, then it inevitably leads to Calvinism.
However, non-Calvinists can be (and are) saved. C.H. Spurgeon famously praised his Evangelical Arminianism Brothers like John Wesley in his, "A Defense of Calvinism."
Consistently Arminian viewpoints as espoused at the Synod of Dort are a False Gospel and Heretical Unbiblical Unchristian views.
However, the difference between Arminianisms then and now means one can be Arminian and still be sticking to enough of the Gospel for one to consider them fellow Christians in the Body of Christ.
However, one is a saved Arminiast despite holding to said views. Very similar to Romanism vs Biblical Christianity.
Although IF Arminianism did equal unsaved God would not be unjust in saving only Calvinists either. I just do not think it is wise nor correct to say the Elect require correct hermeneutics to be saved.