An article about the recent release of a large number of confirmed exoplanets states that most of the 715 newly announced exoplanets orbit very close to their host stars.
Do the theories predict that this is a representative sample and that most planets are very close to their host stars? Or is it just that our current detection techniques are predisposed to finding only those planets close to their stars (because the sensors look for dimming of the host star for example)?
The known exoplanets are not representive. Each discovery technique has its own bias.
For the transit of star technique, the probabilty that a planet transits the star, as observed from a distance, is proportional to the radius of the star and inversely proportional to the orbital radius (semi-major axis). Also, below a certain size, there will be insufficient signal to noise to detect the planet. So the transit technique is biased toward planets orbiting close to their star, planets of larger stars, and planets that are above a signal/noise threshold in size.
The radial velocity of star technique is biased toward finding large mass planets close to their stars.
The direct imaging technique is biased toward finding large planets far away from their stars.
