If line of sight to the Echostar 24 satellite (Jupiter 3) is blocked by trees they won't be able complete the upgrade and you'll stay on the same service you're currently on. I don't believe they would charge for the visit in this case, but I can't say that with 100% certainty.
If it's blocked, they'd be able to tell you right then and there what tree(s) would need to be 'shortened' in order to gain line of sight, as they have a device to tell exactly where the satellite is in the sky, or at least the techs that have been to my house always did.
If it truly is at the same location as the Spaceway 3 (95W), logic dictates that it would also be at the same elevation on the horizon, as all geostationary satellites are at the same altitude above the equator (22,236 miles). So, if you were able to get service from that satellite and nothing has since grown up in that spot to block the line of sight, you should be able to get service from the Echostar 24 without issue. If it has grown up, you may have to do some trimming.