Maybe the could use Bluetooth as backhaul "channel" an Wi-Fi for the devices as a bridge solution
BT doesn't offer the bandwidth or intelligence needed for the uplinks in Mesh networks.
The solution is to use different 5Ghz channels and antenna\chips. If the radio is connecting clients on channel 36, but uses channel 165 for the uplink, traffic will not collide. Think of this like FM radio, if you are tuned to 107.x, you don't hear signals from 91.x. But, to be truely effective, the uplink should use a different signal path (chip+antenna), so client traffic comes in on one radio, and out on a second. This is effectively how roaming Wi-Fi (Apple's term) works when uplinks are via Ethernet, client Wi-Fi connections are forwarded to the router via Ethernet chip versus retransmitting on the same radio\antenna that received the packet.
The thing that slows Wi-Fi down is collisions. The radios can send or receive a single packet at a time on a given frequency, and there are limits to the effectiveness of probing for a clear channel, so radios simply send and hope for the best, then retransmit until they know the packet was received on the other end. If two packets hit a single radio on the same frequency\channel at the same time, one is dropped and the sender must re-transmit. Separating the signal paths allows each chip to capture or send a packet at the same time and let the device manage routing the packets between the signal paths.
BT and 5Ghz range is about 33 feet give or take depending on obstructions, 5Ghz might be a bit longer range due to stronger radio rx\tx strength but is more susceptible to interference from walls, floors, etc. BT uses 2.4Ghz frequencies, so it suffers the same collision\interference problems that 2.4Ghz Wi-Fi does (the reason 5Ghz was developed), but is a weaker signal with less frequency range (bandwidth) to handle the load. BT bandwidth is something to the tune of 25Mbps versus up to 450Mbps for 2.4Ghz Wi-Fi, and 1Gbps+ for 5Ghz 802.11ac. Another way to think of it is BT is like AM radio, and Wi-Fi like FM. FM offers more bandwidth so separate signals are sent in stereo with meta-data (song name, artist, station name) where AM sends a single mono signal with little data (station name). 802.11ac achieves higher speeds with multiple antenna (MIMO) and beam forming (adapting signal strength based on the distance to the peer). So, 802.11b,g,n (2.4 or 5Ghz) vs 802.11ac (5Ghz) can be thought of a bit like stereo (802.11b,g,n) vs 5.1 (802.11ac).
For Mesh gear to be optimized, it must be able to understand all of the nearby radios, what signal frequencies each is using for both the backhaul and client connections, and be able to calculate the best route at any given time to optimize speed. Consider 4 access points (A - D), with A being the router, and B, C, D being roughly equal distance from the router and each other. If the router has 4 radios (1 for client, 3 for the uplinks to each peer access point), then A-B, A-C, and A-D routes should be equal speeds. But, if D is farther from A, but closer to C and B, the best route to D might be A-B-D or A-C-D. These might also change in short bursts due to traffic, or interference, so being able to adapt to the fastest route will optimize speeds. Again, consider D being farther from A, A-B might have a stream of traffic, so A-C-D might be a faster route, but this could reverse in a second or two when clients connected to C start a stream. Add a 5th or 6th access point and the complexity multiplies.
In pre-mesh access points, they identify a single path to the router, using the same antenna\radio and frequencies as client connections, and alternate\retransmit until they succeed. With 4 Access points and numerous client streams, the traffic starts looking like the Interstate at rush hour with several major accidents. In fact, Apple generally states that Wi-Fi uplinks between a router and access point be limited to one, but more access points can be used effectively if you use Ethernet for the uplink signal paths as Ethernet is better at managing the collisions.
Mesh attempts to adapt to alternate paths based on traffic and speed\distance using multiple radio and frequency paths. Mesh requires bandwidth and intelligence to be able to understand and adapt in order to provide sustained increased service levels. BT is not up to this level of complexity, it is designed for near range communications with little management traffic.
[doublepost=1500478009][/doublepost]One more point, the BT Mesh networks they are referring to in this article are the limited bandwidth BT signals which up to now have been a 1-1 type of communication. BT mesh would allow BT devices to forward signals from peers to extend range, but would not offer the kind of bandwidth that Wi-Fi demands. BT is fine for keyboards, mice, headphones, and even Smart Home device management, but not sufficient for Wi-Fi.