Reggeatón is a fusion of the Jamaican pounda beat + Hip Hop and Latin American rhythms and producers like DJ Nelson and DJ Playero were one the firsts to develop this sound in Carolina, Puerto Rico in the mid to late 1990's.
That is not true at all.
Just before 1990, Pichín Román did reggaetón videos all day on his UHF TV channel in San Juan. By that time there was not just enough music, there were enough videos to program the genre all day long.
The earliest songs, though, were from Panama, where artists like El Chombo, El General and JR Ranks were doing tracks in the mid 80's. It then spread to Puerto Rico and by around '89 to '90 Pichín had enough material to program on his TV channel locally. We are talking about pure reggaetón videos all day long.
We used to adjourn after work to a restaurant on Ave. rafael Cordero around the corner from Salsoul where they had that channel on in the bar, always. We came up with a formula where each video had to have at least two of these elements: guns, yachts, mamis, balcón en un departamento en el Condado o Isla Verde, a Mercedes. We'd bet on which elements would be in the next video.
A year or two later, Pichín's San Juan radio station went to an all reggaetón format under manager Jaime Bauzá.
What the Panamanians were doing in the early to mid 1990's in particular is widely known as Reggae en Espanol or Spanish Reggae. They kept the original Jamaican Dance Hall beats, sped up the riddim and sang in Spanish. Often they would sing in Spanish over the popular Jamaican Dance Hall songs keeping the melody and the rhythms. Regardless it was popular in Puerto Rico, Dominican Republic, NYC and South Florida. Yet, it is not Reggaeton.
Since the whole genre is derived from Jamaican beats and influenced by salsa (and not, really, hip hop which was not even played on the radio in PR in the late 80's or earlier 90's) it is obvious that as it developed it kept much of its Jamaican heritage as well as some of the rhythm from salsa and other Caribbean beats.
An example of Reggae Español:
An example of an early underdeveloped Reggaeton Track ( notice the different beat pattern, Techno keys and rapping/ singing style :
Every music form goes through stages of development.