Iirc in the honeymoon years, PLAN officers got to visit aegis destroyers. They know how they work. Aegis is the shield and carrier the sword.
In order for these radars to start appearing in the early to mid 2000s, the groundwork would have begun in the early 1990s. That is consistent to the Chinese article. In order to lay such groundwork and requirements, planners would have already conceived the kind of warfare and the need for a longer ranged air defense bubble even earlier, although back then this was more of a dream than achievable reality. People were thinking far ahead.
I read somewhere but I forgot where I did, that the genesis for the Type 055 goes back earlier, even as early as the '60s. Back then, there were ideas and concepts for a large destroyer, but being economically and technologically unachievable, those concepts were no better than a fanboy's ideas. Those ideas died and resurrected over the coming years, but at some point, "055" has been reserved for a possible large destroyer, although those earlier concepts won't be anywhere close to the ship it is now. What became the real 055 would begin much later, and is now altogether a very different ship, but it inherited the designation reserved for those large concept destroyer.
If I think about it, designations like 057, 058 and 059 may already be reserved as part of some long term planning.