Yes, ECC802S are simply 12AU7's that JJ Tesla designed specifically for Audio applications. They are in the same family and should work in any audio application that requires the 12AU7 tube. See them at the bottom of the 12AU7 list at the Tube Store link I listed.
AudioAsylum is certainly another good resource for information (as well as misinformation). The picture you describe is a very broad generalization, and is not an inaccurate generalization. But there are current production tubes that are excellent choices among specific tube types. NOS tubes are indeed counterfitted (plenty available on eBay to choose from:-). Tubes are also sometimes re-Branded. Also, many manufacturers have some tubes manufactured in different factories in different countries (ie just because it is a Telefunken doesn't mean it was necessarily made in West Germany). For instance, I have some Telefunken E88CC tubes that were made in a Mullard factory in Enland, yet they are marked Telefunken and are not counterfits or re-brands. I have Amperex 12AX7 tubes that are marked "Made in England", that are actually manufactured by Tungsram and were made in Hungary that have been re-branded. Both of these are excellent tubes BTW, even though they are not "accurately" labeled. On the other hand I have a GZ34 rectifier tube that is marked as GE made in England (which should be a Mullard-made tube), but it does not have the hole in the base (a sign of a genuine Mullard GZ34), and has a telltale raised "X" seam on the top of the tube indicating a Japanese counterfit. A very similar kind of "X" seam (though not identical) can also be found on legitimate Siemens tubes which are not counterfits. So, once again, it is good to deal with a tube dealer you know you can trust if you are new to this. Your searches here and on AudioAsylum should give you some good general feedback to go on regarding specific 12AU7 recommendations. Again, good dealers know their tubes VERY well also, and may even know your specific component. Always keep in mind, just as in all aspects of this hobby, there are no hard and fast rules and YMMV. Use your own ears and system to make your own judgements.
AudioAsylum is certainly another good resource for information (as well as misinformation). The picture you describe is a very broad generalization, and is not an inaccurate generalization. But there are current production tubes that are excellent choices among specific tube types. NOS tubes are indeed counterfitted (plenty available on eBay to choose from:-). Tubes are also sometimes re-Branded. Also, many manufacturers have some tubes manufactured in different factories in different countries (ie just because it is a Telefunken doesn't mean it was necessarily made in West Germany). For instance, I have some Telefunken E88CC tubes that were made in a Mullard factory in Enland, yet they are marked Telefunken and are not counterfits or re-brands. I have Amperex 12AX7 tubes that are marked "Made in England", that are actually manufactured by Tungsram and were made in Hungary that have been re-branded. Both of these are excellent tubes BTW, even though they are not "accurately" labeled. On the other hand I have a GZ34 rectifier tube that is marked as GE made in England (which should be a Mullard-made tube), but it does not have the hole in the base (a sign of a genuine Mullard GZ34), and has a telltale raised "X" seam on the top of the tube indicating a Japanese counterfit. A very similar kind of "X" seam (though not identical) can also be found on legitimate Siemens tubes which are not counterfits. So, once again, it is good to deal with a tube dealer you know you can trust if you are new to this. Your searches here and on AudioAsylum should give you some good general feedback to go on regarding specific 12AU7 recommendations. Again, good dealers know their tubes VERY well also, and may even know your specific component. Always keep in mind, just as in all aspects of this hobby, there are no hard and fast rules and YMMV. Use your own ears and system to make your own judgements.